Answer: 1/30
Step-by-step explanation:
Here's the correct question:
A dump truck brought 1⁄3 of a ton of rock on the first trip, 1⁄2 of a ton on the second trip, but on the third trip, had to take back 4⁄5 of a ton. What was the total weight of the rock left at the construction site?
To calculate the the total weight of the rock left at the construction site goes thus:
= 1/3 + 1/2 - 4/5
The lowest common multiple of 3,2 and 5 is 30. Therefore, we'll make the fractions have a common denominator.
= 1/3 + 1/2 - 4/5
= 10/30 + 15/30 - 24/30.
= 1/30
