GMAT Exam  >  GMAT Questions  >  The arithmetic mean (average) of a set of 5 n... Start Learning for Free
The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?
I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180 
II. When B is divided by 60, the remainder is 30
III. The value of the decimal digits is greater in the number   than in the number 
  • a)
    I only
  • b)
    II only
  • c)
    III only
  • d)
    I and II only
  • e)
    I and III only
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
The arithmetic mean (average) of a set of 5 numbers is an integer A. U...
  • Let the set of 5 numbers be {p, q, r, s, t}
  • Arithmetic Mean of this set = A
  • A is an integer 
  • A = 180q + 30, where quotient q is an integer
  • When 2 numbers in the set are decreased by 120 and 180, the new Arithmetic Mean is B
To find: Which of the 3 statements is/are true?
Approach:
  • Looking at the statements, we realize that to answer the question, we need to find an equation for B (to find the remainder that B leaves with certain divisors) and also a relation between A and B
  • We’ll use the given information to find these 2 information points
    • Since we are given the decrease in 2 numbers of the set, we can find the total decrease in the sum of the 5 numbers (with respect to the original sum of the 5 numbers). By expressing the original sum of the 5 numbers and the decreased sum in terms of A and B respectively, we can find a relation between A and B
    • Since we know an equation for A, we can use the relation between A and B to find an equation for B. 
  • Then, we’ll evaluate the 3 statements one by one.
  • Working Out:
  • Finding a relation between A and B
    • When 2 numbers in the set are decreased by 120 and 180, the new Arithmetic Mean is B
      • 120 + 180 = 300
    • So, when the sum p  +q + r + s + t is decreased by 300, the new mean is B
Thus, B = A – 60
  • Evaluating Statement I
  • The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180 
    • The remainder that A leaves with 180 is 30
    • From the equation B = 180(q-1) + 150, it is clear that the remainder that B leaves with 180 is 150
    • Since 150 is greater than 30, Statement I is not true.
 
  • Evaluating Statement II
  • When B is divided by 60, the remainder is 30
    • Rearranging the equation B = 180(q-1) + 150:
      • B = 180(q-1) + 120 +30
      • B = {180(q-1) + 120} + 30
    • From the above form of the equation, it’s clear that when B is divided by 60, the term {180(q-1) + 120} will be divisible by 6. The leftover term, 30, is positive and is less than the divisor 60. So, it passes both the tests for being a remainder.
    • Therefore, when B is divided by 60, the remainder is 30
    • Statement II is true.
       
  • Evaluating Statement III
  • The value of the decimal digits is greater in the number   than in the number  
  • A = 180q + 30
  • So, when A is divided by 90, the term 180q is divisible by 90. The decimal digits come from the part 
  • B = 180(q-1) + 150 = {180(q-1) + 90}  + 60
  • So, when B is divided by 90, the term {180(q-1) + 90} is divisible by 90. The decimal digits come from the part 
  • Therefore, the value of the decimal digits is greater in
  • So, Statement III is not true.
  • Getting to the answer
    • Thus, we see that only Statement II is true.
Looking at the answer choices, we see that the correct answer is Option B
View all questions of this test
Explore Courses for GMAT exam

Similar GMAT Doubts

Top Courses for GMAT

The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer?
Question Description
The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer? for GMAT 2024 is part of GMAT preparation. The Question and answers have been prepared according to the GMAT exam syllabus. Information about The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for GMAT 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer?.
Solutions for The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for GMAT. Download more important topics, notes, lectures and mock test series for GMAT Exam by signing up for free.
Here you can find the meaning of The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice The arithmetic mean (average) of a set of 5 numbers is an integer A. Upon being divided by 180, A leaves a remainder of 30. If two of the numbers in the set are decreased by 120 and 180 units respectively, which of the following statements must be true about the new arithmetic mean B of the set?I. The remainder that B leaves upon division by 180 is less than the remainder that A leaves upon division by 180II. When B is divided by 60, the remainder is 30III. The value of the decimal digits is greater in the number than in the numbera)I onlyb)II onlyc)III onlyd)I and II onlye)I and III onlyCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice GMAT tests.
Explore Courses for GMAT exam

Top Courses for GMAT

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev