If the seven-digit number 74x29y6 is divisible by 72, then what will be the value of (2x + 3y)?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 19
To divide the given number by 72, the number should be divisible by both 8 and 9.
It is divisible by 8 when 9y6 is divisible by 8.
so y = 3 or 7
The given number is divisible by 9 when the sum of digits divisible by 9.
so, 7 + 4 + x + 2 + 9 + y + 6 = 28 + x + y
if y = 3, 31 + x should be 36 ⇒ x = 5 ⇒ (2x + 3y) = 19
if y = 7, 35 + x should be 36 ⇒ x = 1 ⇒ (2x + 3y) = 23
As per options answer is 19.