Complete question is;
The city just assigned a second garbage truck to empty the bins in Kat’s neighborhood on trash day. The crew from the first garbage truck used to empty all the bins by themselves in 5 hours. In their training, it took the crew from the second garbage truck 8 hours to empty all the bins. When the two crews start working together, what part of all the garbage bins will the first garbage truck empty? To the nearest tenth, the first garbage truck will empty about of all the bins.
Answer:
Part of all bins first garbage truck will empty = 0.6
Explanation:
Let the total number of bins emptied be denoted by n.
We are told that the crew from the first garbage truck empties all the bins in 5 hours. Thus
Work rate = (n/5) bins/hr
We are told the second garbage truck empties in 8 hours. Thus;
Work rate = (n/8) bins/hr
When both garbage trucks work together, the total amount of time spent will be denoted by x. Thus;
((n/5) + (n/8))x = n
Divide through by n to get;
x/5 + x/8 = 1
Multiply through by 40 to gwt;
8x + 5x = 40
13x = 40
x = 40/13 hrs
To find the part of all the garbage bins the first garbage truck empty when they work together, we will simply multiply the value of x by the work rate of the first garbage truck. Thus;
Part = (n/5) × (40/13)
Part = (40/65)n = 0.615 of n
To the nearest tenth gives 0.6 of n