Question

The average length of time that three lawn-service mowers operate on a given day is 930 minutes. None of the mowers operates for less than 900 minutes. What is the greatest possible length of time any of the mowers operates?A. 990
B. 950
C. 960
D. 900
E. 930

Answer 1

Answer:

The answer is A. 990.

Step-by-step explanation:

Now, to find the greatest possible length of time any of the mowers operates.

The 3 lawn-service mowers operate at the average length of time = 930 minutes.

So, the total length of time the 3 lawn mowers take = $930\times 30=2790\ minutes.$

The least length a mowers operates = 900 minutes.

Now, to find the greatest possible length of time any of the mowers operates:

Let $x$ be the greatest possible length of time any of the mowers operates.

As, any one of the mowers operates greatest length.

So, rest of the two mowers be least at length.

According to question:

$x+900+900=2790$

$x+1800=2790$

Subtracting both sides by 1800 we get:

$x=2790-1800$

$x=990.$

Thus, the greatest possible length of time any of the mowers operates is 990 minutes.

Therefore, the answer is A. 990.