Average speed in miles per hour is the number of miles traveled divided by the number of hours:

Solving for time:

time = \( \frac{\text{distance}}{\text{speed}} \)
time = \( \frac{180mi}{60mph} \)
3 hours

The least common multiple (LCM) is the smallest positive integer that is a multiple of two or more integers.

To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80] and the first few multiples of 12 are [12, 24, 36, 48, 60, 72, 84, 96]. The first few multiples they share are [24, 48, 72, 96] making 24 the smallest multiple 8 and 12 share.

Next, convert the fractions so each denominator equals the lowest common multiple:

\( \frac{5 x 3}{8 x 3} \) + \( \frac{6 x 2}{12 x 2} \)

\( \frac{15}{24} \) + \( \frac{12}{24} \)

Now, because the fractions share a common denominator, you can add them:

\( \frac{15 + 12}{24} \) = \( \frac{27}{24} \) = 1\(\frac{1}{8}\)

To raise a term with an exponent to another exponent, retain the base and multiply the exponents:

A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.