SOLUTION: A car factory produced 20 cars in a day. After the equipment was renovated and another one was brought to the factory, the factory started to produce 70 cars per day. By what perce

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: A car factory produced 20 cars in a day. After the equipment was renovated and another one was brought to the factory, the factory started to produce 70 cars per day. By what perce      Log On


   

Question 1153252: A car factory produced 20 cars in a day. After the equipment was renovated and another one was brought to the factory, the factory started to produce 70 cars per day. By what percent did the speed of car production increase?
Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39617) About Me  (Show Source):
Answer by greenestamps(13200) About Me  (Show Source):
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The answer by tutor @josgarithmetic is wrong.

The old rate was 20 cars per day; the new rate is 70 cars per day.

That means the INCREASE in the rate is 50 cars per day.

And that means the PERCENT INCREASE in the rate is

%2850%2F20%29%2A100 = 250%.

The new rate is 350% OF the old rate; but it is 250% MORE THAN the old rate.