Question

if 25776a456b is divisible by 15. Then find possible values of a, b (both are digits).​

Answer 1

Step-by-step explanation:

The given number is 2576a456b

To be divisible by 15, the number has to divisible by both 3 and 5.

As per divisibility rule for 5, the last digit should be 0 or 5

so b can be 0 or 5

So option B is correct.

Now we take both cases of value of b.

Case - 1: when b=0

Now the given number becomes 2576a4560

For a number to be divisible by 3, the sum of its digits should be divisible by 3.

Thus the sum of digits of this number is 35+a

For 35+a to be divisible by 3, a can be anything from 1,4,7,10....

So option C is correct.

Now Case-2: when b=5

Now the given number becomes 2576a4565

Thus the sum of digits of this number is 40+a

For 40+a to be divisible by 3, a can be anything from 2,5,8,11....

I hope this helps to you !!!

cs.