Select the correct answer. Given the following formula, solve for y.
I - y
W =
- 2
2
OA.
y = – 2(w + 2)
OB.
y = 2(w + 2) – x
y = -
(20 + 2)
D.
y = 2 + 2 – D

to find the total number of combinations, multiply the quantity of each item by each other:

2 pairs of shoes x 3 pairs of shorts = 6 different combinations.

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

source: