Question

Hi! So I multiplied 30 x 12 and got 36. Why do you add 4 to get 40 as the answer?

Answer 1

The given information is:

- The students complete 30% of the project in 12 hours.

To find how many hours they will need to finish the project we need to apply ratios, as follows:

`\begin{gathered} \frac{30\%\text{ of the project}}{made\text{ in 12 hours}}=\frac{100\%}{how\text{ many hours will it take?}} \\ \\ (30)/(12)=(100)/(x) \\ \\ Let^(\prime)s\text{ solve for x:} \\ Multiply\text{ both sides by x:} \\ x*(30)/(12)=(100)/(x)*x \\ \\ Simplify \\ x*(30)/(12)=100 \\ \\ Multiply\text{ both sides by 12/30} \\ x*(30)/(12)*(12)/(30)=100*(12)/(30) \\ \\ Simplify \\ x=(100*12)/(30) \\ \\ x=(1200)/(30) \\ \\ x=40\text{ hours} \end{gathered}`

The answer is 40 hours.