∵2^m=3,2^n=4,2^k=5
∴2^(m-2n+3k)
=2^m÷2^(2n)×2^(3k)
=3÷(2^n)²×(2^k)³
=3÷4²×5³
=3÷16×125
=375/16
=23又7/16