Question

Yesterday, Brainy Games sold robots and chess sets in the ratio 3:5. The store sold 21 robots. How many toys were sold in all?

Answer 1

`\begin{gathered} \frac{robots}{\text{chess sets}}\colon(3)/(5)=(21)/(x) \\ \end{gathered}`

solve for x

`\begin{gathered} 3x=21*5 \\ 3x=105 \\ (3x)/(3)=(105)/(3) \\ x=35 \end{gathered}`

the store sold 35 chess sets

and answer is: 21 robots + 35 chess sets = 56 toys sold by the store