2023 · Q31
The eight-digit number 789459xy is divisible by 88, where x and y are digits. What are the possible values of x and y?
General Mental Ability, Quantitative Aptitude and StatisticsNumber system and arithmetic
- Ax = 1, y = 2
- Bx = 2, y = 2
- Cx = 3, y = 6
- Dx = 4, y = 4
Explanation
A number divisible by 88 must be divisible by both 8 and 11. The last three digits are '9xy': among the options, 912 (option a) and 944 (option d) are divisible by 8, while 922 and 936 fail or fail the next test. Applying the divisibility rule for 11 to the full number, only x = 4, y = 4 gives an alternating digit sum difference of zero (4-4+9-5+4-9+8-7 = 0). Hence (d) is correct.