Question

A geologist have two rocks on a scale that weighs 2 1/2 lbs together rock a was 1/7 of a the total weight how much did rock a weight

Answer 1

Simply get the product of 2 and 1/2 by 1/7.

firstly, let's convert the mixed fraction to "improper" and then multiply.

$\bf \stackrel{mixed}{2\frac{1}{2}}\implies \cfrac{2\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{5}{2}}\qquad \qquad \cfrac{5}{2}\cdot \cfrac{1}{7}\implies \stackrel{\textit{rock A weight}}{\cfrac{5}{14}}$