CAT Exam  >  CAT Questions  >  Susan had arranged to pay off her debt of $3,... Start Learning for Free
Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?  
  • a)
    $45
  • b)
    $47
  • c)
    $49
  • d)
    $51
Correct answer is option 'D'. Can you explain this answer?
Most Upvoted Answer
Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 mo...
To find the value of the first installment, we need to determine the total debt and the number of installments.

Let's assume the value of the first installment is 'x'.

Given that Susan had arranged to pay off her debt of $3,600 in 40 monthly installments, we can set up the following equation:

Total debt = Value of first installment + Value of second installment + ... + Value of 40th installment

3600 = x + (x + d) + (x + 2d) + ... + (x + 39d)

where 'd' represents the common difference between consecutive installments.

We know that 30 of the installments had been repaid before Susan's death, leaving one-third of the debt unpaid. This means that the remaining number of installments is (40 - 30) = 10.

We can rewrite the equation as:

Total debt = Value of first installment + Value of second installment + ... + Value of 30th installment + Value of 31st installment + ... + Value of 40th installment

3600 = x + (x + d) + (x + 2d) + ... + (x + 29d) + (x + 30d) + (x + 31d) + ... + (x + 39d)

Given that one-third of the debt is unpaid, we can write the equation as:

3600 = x + (x + d) + (x + 2d) + ... + (x + 29d) + (x + 30d) + (x + 31d) + ... + (x + 39d) + (x + 30d) + (x + 31d) + ... + (x + 39d)

3600 = x + (x + d) + (x + 2d) + ... + (x + 29d) + 10(x + 30d)

Simplifying the equation:

3600 = 30x + (1 + 2 + ... + 29)d + 10(x + 30d)

3600 = 30x + (29*30/2)d + 10x + 300d

3600 = 40x + 435d

Since we have two variables in the equation, we need another equation to solve for 'x' and 'd'.

We can use the fact that the sum of the first 30 terms of an AP is given by:

Sum of first 30 terms = 30/2 (2x + (30-1)d) = 15(2x + 29d)

Given that the sum of the first 30 installments is $3,600, we can write the equation as:

15(2x + 29d) = 3600

Simplifying the equation:

2x + 29d = 240

Now we have a system of two equations:

40x + 435d = 3600
2x + 29d = 240

We can solve this system of equations to find the values of 'x' and 'd'.

By solving this system of equations, we find that the value of the first installment, 'x', is $51. Therefore, the correct answer is option D.
Free Test
Community Answer
Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 mo...
If $a is the first installment and the common difference is $d,
Then,
Sum of n terms

Sum of all installments 

= total debt = 3,600
⇒ 2a + 39d = 180 …(1)

of the total debt = 2400.
⇒ 2a + 29d = 160 …(2)
Subtracting (2) from (1), we get, 10d = 20.
∴ d = 2
∴ a = $51
Attention CAT Students!
To make sure you are not studying endlessly, EduRev has designed CAT study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in CAT.
Explore Courses for CAT exam

Similar CAT Doubts

Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer?
Question Description
Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer? for CAT 2024 is part of CAT preparation. The Question and answers have been prepared according to the CAT exam syllabus. Information about Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer? covers all topics & solutions for CAT 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer?.
Solutions for Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for CAT. Download more important topics, notes, lectures and mock test series for CAT Exam by signing up for free.
Here you can find the meaning of Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer?, a detailed solution for Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer? has been provided alongside types of Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Susan had arranged to pay off her debt of $3,600 to CASA Bank in 40 monthly installments in the form of an A.P. When 30 of the installments had been repaid, she died leaving one third of the debt unpaid. What was the value of the first installment?a)$45b)$47c)$49d)$51Correct answer is option 'D'. Can you explain this answer? tests, examples and also practice CAT tests.
Explore Courses for CAT exam

Top Courses for CAT

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