#### Answer

$6mn^{3}$

#### Work Step by Step

You have the expression: 2$m^{3/4}$$n^{2}$ $\times$ 3$m^{1/4}$n.To simplify you have to add the exponents of numbers with the same base:
(2$\times$3)($m^{3/4+1/4}$)($n^{2+1}$) -when multiplying the powers with the same base add the exponents-
=$6mn^{3}$