Question

A road crew can pave 2/5 km in 1 1/2 hours.how many km of road can they pave in 10 hours?

Answer 1

Answer:

8/3 km

Step-by-step explanation:

we can represent the given information on a table:

Kilometers        time (hours)

      2/5           ⇔         1 1/2

and since we want to know how many kilometers (x) will be paved on 10 hours:

Kilometers        time (hours)

      2/5           ⇔         1 1/2

        x             ⇔         10

The relationship these 3 numbers have can be described by using the rule of three, which is to multiply the cross quantities on the table (2/5 by 10) and then divide by the remaining amount (1 1/2):

x = $\frac{2}{5}*10$ ÷ $1\frac{1}{2}$

x = $\frac{20}{5}$ ÷ $1\frac{1}{2}$

we use $1\frac{1}{2}=\frac{3}{2}$

x = $\frac{20}{5}$ ÷ $\frac{3}{2}$

and we make the division:

x = $\frac{20}{5}$ ÷ $\frac{3}{2}$ = $\frac{20*2}{5*3}=\frac{40}{15}$

we simplify the fraction by dividing the numerator and denominator both by 5, and we get the result:

x = $\frac{8}{3}$

thus, in 10 hours the crew will pave 8/3 km. Which is about 2.66 km.