Question

you work as a supervisor for a mining firm. at your site, a tramway carries 3 tons of ore every 1 hour 30 minutes. working at this rate, how many hours will it take to transport 45 tons of ore?
a. 3.3
b. 6.5
c. 7.5
d. 11.7
e. 18.5

Explanation:

Step1: Convert time to hours

1 hour 30 minutes = 1.5 hours.

Step2: Find the rate of transportation

The rate is 3 tons per 1.5 hours, so the rate $r=\frac{3}{1.5}=2$ tons per hour.

Step3: Calculate the time for 15 tons

Let $t$ be the time. We know that rate $\times$ time = amount. So $t=\frac{15}{2}=7.5$ hours.

Answer:

C. 7.5