Christine scored 88% on the test meaning she earned 88% of the possible points on the test. There were 80 possible points on the test so she earned 80 x 0.88 = 70 points. Each question is worth 2 points so she got \( \frac{70}{2} \) = 35 questions right.

A factorial is the product of an integer and all the positive integers below it. To solve a fraction featuring factorials, expand the factorials and cancel out like numbers:

\( \frac{6!}{4!} \)
\( \frac{6 \times 5 \times 4 \times 3 \times 2 \times 1}{4 \times 3 \times 2 \times 1} \)
\( \frac{6 \times 5}{1} \)
\( 6 \times 5 \)
30

To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{4}{5} \) x \( \frac{3}{6} \) = \( \frac{4 x 3}{5 x 6} \) = \( \frac{12}{30} \) = \(\frac{2}{5}\)

To divide fractions, invert the second fraction and then multiply:

\( \frac{1}{7} \) ÷ \( \frac{3}{5} \) = \( \frac{1}{7} \) x \( \frac{5}{3} \)

To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{1}{7} \) x \( \frac{5}{3} \) = \( \frac{1 x 5}{7 x 3} \) = \( \frac{5}{21} \) = \(\frac{5}{21}\)

By buying two shirts, Monty will save $43 x \( \frac{25}{100} \) = \( \frac{$43 x 25}{100} \) = \( \frac{$1075}{100} \) = $10.75 on the second shirt.

So, his total cost will be
$43.00 + ($43.00 - $10.75)
$43.00 + $32.25
$75.25