Question

If 21a7 is divisible by 9 then which digit Can replace the letter a in the 4-digit number 21a7​

Answer 1

Answer:

2187

Step-by-step explanation:

A number is said be divisible by 9 when the sum of the digits in a number is divisible by 9

⇒ 21a7 ⇒ sum of digits = 2 + 1 + a + 7 = 10 + a should be divisible by 9

out of 0 to 9 digits the only chance of a is 8 so that 10 + a = 10 + 8 = 18 is divisible by 9

so the number is 2187 where a = 8