A purse contains 4 copper coins and 3 silver coins, the second purse contains 6 copper coins and 2 silver coins. If a coin is drawn out of any purse, then the probability that it is a copper coin is

$\frac{4}{7}$ $\frac{3}{4}$ $\frac{37}{56}$ None of these

$\frac{37}{56}$

Required probability $=\frac{1}{2}.\frac{4}{7}+\frac{1}{2}.\frac{6}{8}=\frac{37}{56}.$