Question

A purse contains 4 copper coins, 3 silver coins and the second purse contains 6 copper coins and 2 silver coins. If a coins is taken out of any purse then what is the probability that it is a copper coin.
A. `41//70`
B. `31//70`
C. `27//70`
D. `1//3`

Answer 1

Correct Answer - A
`P_(1):"4 copper coins 3 silver coins"`
`P_(2):"6 copper coins 4 silver coins"`
E = Event of copper coin
`P(E)=P(P_(1)).P_((E//P_(1)))+P(P_(2)).P(E//P_(2))`
`=(10)/(2)xx(4)/(7)+(1)/(2)xx(6)/(10)`
`=(41)/(70)`