Question

bob wants to buy 150 dL of soda if 7.65 L cost $9.40 then how much will he pay for 150 dL

Answer 1

In order to determine the cost of 150 dL, first convert this quantity to L, as follow:

$150dL\cdot\frac{1L}{10dL}=15L$

where we have use the equivalence 1L = 10dL.

Next, if 7.65L cost $9.40, then, by using rule of three you can write:

$\frac{x}{15L}=\frac{9.40}{7.65L}$

where x is the cost of 15L. Then, by solving for x and by simplifying we obtain:

$\begin{gathered} x=\frac{9.40}{7.65}\cdot15L \\ x\approx14.4 \end{gathered}$

Hence, 150dL cost approximately $14.4