If the nine-digit number 87605x31y is divisible by 72, then the value of (2x - 3y) is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 2.
9 digit number 87605x31y is divided by 72,
Hence it can be said that the number is also divisible by 8 and 9 both
The number to be divisible by 8, should have the last 3 digits divisible by 8
⇒ 31y will be divisible by 8 if y = 2
A number will be divisible by 9 if the sum of the digits is divisible by 9
⇒ 87605x312 will be divisible by 9 if x = 4
⇒ (2x - 3y) = (2 × 4) - (3 × 2) = 2