Act Math Practice

Pre-Algebra Answer 2

Pre-Algebra Answer 2:

2. A flight with a low-cost airline travels 9 ´ 10³ miles per hour for 3 ´ 10^-2 hours. How far has this cheap flight traveled?

F. 135 miles

G. 270 miles

H. 900 miles

J. 1350 miles

K. 2700 miles

The correct answer is G.

Remember that when the base numbers are the same and you need to multiply, you can add the exponenents.

However, when the base numbers are the same and you need to divide, you can subtract the exponenents.

In this problem, we need to multiply the miles per hour times the number of hours in order to calculate the distance traveled.

Since we have the base number of 10 for each number that has an exponent, we can add the exponent of 3 to the exponent of -2:

(9 ´ 10³ miles per hour) ´ (3 ´ 10^-2 hours) =
9 ´ 3 ´ 10^{(3 + -2)} =
9 ´ 3 ´ 10¹ =
9 ´ 3 ´ 10 = 270 miles

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