A 0.24 g sample of compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.

Here's some tips:

There are formulas that explain percent as a part to whole ratio, For each percent you are going to have 1/100th of the whole. Boron is .096/.24ths of the whole. How many percents equal Boron? Lets set up an equation.

\frac{0.096}{0.24} = \frac{x}{100}

Give it a try, post your results, we can help from there.

Try to set up the equation for percent of oxygen.