A man loses $\frac{1}{3}$ of money in first round,$\frac{3}{5}$ of remaining in second,$\frac{4}{7}$ of remaining in third.Find the amount he is left with.

Let M = His money

1 - He loses 1/3 in the first round, which means he has: 2/3M left.

2 - He loses 3/5 of the remainning, which means he has:2/3M * 2/5 ==4/15M left.

3 - He loses 4/7 of the remainning, which means he has:4/15M * 3/7==4/35M left.