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

$\begin{gathered} x\times84=9\times1 \\ 84x=9 \end{gathered}$

divide both sides by the coefficient of x which is 84

$\begin{gathered} \frac{84x}{84}=\frac{9}{84} \\ x=0.107 \end{gathered}$

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

$\begin{gathered} 9\times x=16\times1 \\ 9x=16 \end{gathered}$

divide both sides by the coefficient of x which is 9

$\begin{gathered} \frac{9x}{9}=\frac{16}{9} \\ x=1.7 \end{gathered}$

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