Question

If m,n are natural numbers ,for what values of m,does 2^×5^ ends in 5

Answer 1

Answer:

2n is always even for all values of n. 5m is always odd and ends with 5 for all values of m. But 2n × 5m is always even and ends in 0. ∴ 2n × 5m cannot end with the digit 5 for any values of m.

Answer 2

Answer:

2n is always even for all values of n. 5m is always odd and ends with 5 for all values of m. But 2n × 5m is always even and ends in 0. ∴ 2n × 5m cannot end with the digit 5 for any values of m.