Question

Find the least number which should replace in the number 97*4 to make it exactly divisible by
i) 3 ii)9. Also, write the divisibility rule of 3 & 9.

Answer 1

Answer:

The divisibility of 3 &9 is that the sum of digit should be divisible by both 3&5

in this case 9+7+x+4=20+x

so if we put x = 1 than it becomes 21 which is divisible by 3 but not 9 so this can't be our ans

now if we put x=7 than it becomes 27 which is divisible by both 3 &9

so least number is 7