By buying two shirts, Damon will save $45 x \( \frac{45}{100} \) = \( \frac{$45 x 45}{100} \) = \( \frac{$2025}{100} \) = $20.25 on the second shirt.

So, his total cost will be
$45.00 + ($45.00 - $20.25)
$45.00 + $24.75
$69.75

Monica scored 77% on the test meaning she earned 77% of the possible points on the test. There were 180 possible points on the test so she earned 180 x 0.77 = 138 points. Each question is worth 3 points so she got \( \frac{138}{3} \) = 46 questions right.

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

Solving for distance:

distance = \( \text{speed} \times \text{time} \)
distance = \( 15mph \times 3h \)
45 miles

To add these fractions, first find the lowest common multiple of their denominators. The first few multiples of 2 are [2, 4, 6, 8, 10, 12, 14, 16, 18, 20] and the first few multiples of 8 are [8, 16, 24, 32, 40, 48, 56, 64, 72, 80]. The first few multiples they share are [8, 16, 24, 32, 40] making 8 the smallest multiple 2 and 8 share.

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

\( \frac{5 x 4}{2 x 4} \) + \( \frac{2 x 1}{8 x 1} \)

\( \frac{20}{8} \) + \( \frac{2}{8} \)

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

\( \frac{20 + 2}{8} \) = \( \frac{22}{8} \) = 2\(\frac{3}{4}\)

The factors of a number are all positive integers that divide evenly into the number. The factors of 40 are 1, 2, 4, 5, 8, 10, 20, 40.