Question

(a) Chau runs 9 miles in 84 minutes.How many miles does he run per minute? miles per minute (b)Kala bought 16 pounds of flour for$9 .How many pounds of flour did she get per dollar?pounds per dollar

Answer 1

hello

to solve this question, we simply need to equate it to both sides

`\begin{gathered} 9\text{miles}=84\text{minutes} \\ \text{xmiles}=1\text{minute} \end{gathered}`

cross multiply both sides and make x the subject of formula

`\begin{gathered} x*84=9*1 \\ 84x=9 \end{gathered}`

divide both sides by the coefficient of x which is 84

`\begin{gathered} (84x)/(84)=(9)/(84) \\ x=0.107 \end{gathered}`

from the calculation above, Chau will cover 1 mile in 0.107 minutes

b)

we apply the same principle used above for a in this question

`\begin{gathered} 16\text{pounds}=\text{ \$9} \\ \text{x pounds= \$1} \end{gathered}`

cross multiply both sides and make x the subject of formula

`\begin{gathered} 9* x=16*1 \\ 9x=16 \end{gathered}`

divide both sides by the coefficient of x which is 9

`\begin{gathered} (9x)/(9)=(16)/(9) \\ x=1.7 \end{gathered}`

from the calculation above, Kala bought 1.7 pounds for $1