Question

if a number is divisible by 9 and 10 both then it must be divisible by 90 true or false

Answer 1

9 and 10 are co primes , so their multiple would be 90. In coprime rule , any no. divisible by both coprimes will also be divisible by their multiple , for example - 3 and 4 are coprimes , their multiple is 12, any no. like 36 is divisible by both 3 and 4 , so it will also be divisible by their multiple 12.
Therefore, it's true

Answer 2

Here is your answer

Yes it is true because the first number Which is divisible by 9&10 is 90 then180 then 270 ...... So yes will be the answer

Hope it will help you my friend...