A radioactive nucleus, X_{1}, decays into a second radioactive nucleus, X _{2}. The halflife of X_{1} is 30.4 min, and the halflife of X _{2} is 2.5 min. If a radioactive sample begins with 5 g of X _{1} and 10 g of X_{2}, how many grams of X _{2} will there be after 5 minutes?