If the seven-digit number 35345xy is divisible by 40, then the least value of (4x + 5y) is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 8.
Given number is divisible by 40, i.e. the number if divisible by both 5 and 8.
Divisibility of 5: If the last digit of the number if either 0 or 5, the number is divisible by 5.
Divisibility rule of 8: If the last 3 digits of a number is divisible by 8, the number is divisible by 8.
Given, 35345xy
Now, y = 0 then x = 2
⇒ 4x + 5y = 8
Also x, y = 6, 0
⇒ 4x + 5y = 24
Hence the least number is 8.