Q6. If $2^{n-7}\times 5^{n-4}=1250$, find the value of n.

1250=2x5^4
2^(n-7)x 5^(n-4)=1250
2^(n-7)x 5^(n-4)=2x5^4
n=8

Therefore, the value of n is 8.