If a seven-digit number 53345xy is divisible by 40, for some possible values of x and y, then the one value of (2x - 5y) is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 12.
40 = 5 × 8
Divisibility rule of 5: the last digit should be 5 or 0
to make divisible by 5 as well as 8 last digit must be 0
so, y = 0
Divisibility rule of 8: the last three digits are divisible by 8
last 3 digits = 5x0
x = 2, 6
So, (2x - 5y) = (2 × 6 - 5 × 0) = 12