Is 87 divisible by 7

No, 87 is not divisible by 7. To determine if a number is divisible by 7, you can use the rule that states a number is divisible by 7 if the difference between twice the digit in the ones place and the number formed by the other digits is either 0 or a multiple of 7. In this case, the number formed by the other digits is 8, and twice the digit in the ones place is 14. The difference between 14 and 8 is 6, which is not a multiple of 7, so 87 is not divisible by 7.