What is the remainder when the positive integer x is divided by 6?Stat...
Step 1: Decode the Question Stem and Get Clarity
Q1. What kind of an answer will the question fetch?
The question asks us to find the remainder when x is divided by 6.
The data provided in the statements will be considered sufficient if we get a unique value for the remainder.
Q2. When is the data not sufficient?
If after using the information given in the statements, we are not able to determine a unique remainder when x is divided by 6, the data given in the statements is not sufficient to answer the question.
Q3. What information do we have about x from the question stem?
x is a positive integer.
Step 2: Evaluate Statement 1 ALONE
Statement 1: When x is divided by 7, the remainder is 5.
Approach 1: x can therefore, be expressed as 7k + 5
If k = 0, x = 5. The remainder when x is divided by 6 will be 5.
If k = 1, x = 12. The remainder when x is divided by 6 will be 0.
The remainder varies as the value of k varies.
Approach 2: List numbers (about 10 to 12) that satisfy the condition given in statement 1 and check whether you get a unique remainder.
x could be 5, 12, 19, 26, 33, 40, 47, 54, 61, 68, 75, 82, 89 .....
The remainders that we get correspondingly are 5, 0, 1 and so on
As seen with Approach 1, we are not getting a unique remainder.
We are not able to get a unique remainder using statement 1.
Hence, statement 1 is not sufficient.
Eliminate answer options A and D.
Step 3: Evaluate Statement 2 ALONE
Statement 2: When x is divided by 9, the remainder is 3.
Approach 1:: x can be expressed as 9p + 3
If p = 0, x = 3. Hence, the remainder when x is divided by 6 will be 3.
If p = 1, x = 12. The remainder when x is divided by 6 will be 0.
The remainder varies as the value of k varies.
Approach 2:: List numbers (about 10 to 12) that satisfy the condition given in statement 2 and check whether you get a unique remainder.
x could be 3, 12, 21, 30, 39, 48, 57, 66, 75, 84, 93 .....
The remainders that we get correspondingly are 3, 0, 3 and so on.
As seen with Approach 1, we are not getting a unique remainder.
We are not able to get a unique remainder using statement 2.
Hence, statement 2 is not sufficient.
Eliminate answer option B.
Step 4: Evaluate Statements TOGETHER
Statements: When x is divided by 7, the remainder is 5 & When x is divided by 9, the remainder is 3.
Approach 1:: Equating information from both the statements, we can conclude that 7k + 5 = 9p + 3.
Or 7k = 9p - 2.
i.e., 9p - 2 is a multiple of 7. When p = 1, 9p - 2 = 7. So, one instance where the conditions are satisfied is when k = 1 and p = 1.
x will be 12 and the remainder when x is divided by 6 is 0.
When p = 2, 9p - 2 is not divisible by 7. Proceeding by incrementing values for p, when p = 8, 9p - 2 = 70, which is divisible by 7.
When p = 8, x = 75.
The remainder when 75 is divided by 6 is 3.
The remainder when x was 12 was 0. The remainder when x is 75 is 3.
Approach 2:: The values of x that satisfy statement 1 are 5, 12, 19, 26, 33, 40, 47, 54, 61, 68, 75, 82, 89 ...
The values of x that satisfy statement 2 are 3, 12, 21, 30, 39, 48, 57, 66, 75, 84, 93 .....
Values of x that are present in both sets are 12, and 75 from the set listed above.
The remainders when 12 and 75 are divided by 6 are 0 and 3 respectively.
We are not able to get a unique remainder despite combining the two statements, the data provided is NOT sufficient.
Hence, statements together are not sufficient.
Eliminate answer option C.
Choice E is the correct answer.