Explanation:
the key is to understand that
12 in = 1 ft
1 ft³ (= a cube of 1 ft × 1ft × 1ft or 12in × 12 in × 12 in = 1728 in³) weighs 40 lbs.
her truck can only carry 1,700 lbs without breaking down.
but it would have space for 66×60×24 = 95040 in³ =
95040/1728 = 55 ft³ of soil, which would weigh
55 × 40 = 2200 lbs (too much for the truck).
the same ratio as for the weight her truck can carry applies for the filled volume of the truck bed with that weight :
1700/2200 = 17/22
so, she can only fill 17/22 of her truck bed volume with soil.
i)
percents are calculated by multiplying the ratio by 100 :
17/22 × 100 = 77.27272727... % ≈ 77%
she can fill about 77% of her truck bed with soil without going over the weight limit.
ii)
since she can transport only 1700 lbs in one trip, and 1 ft³ of soil weighs 40 lbs, she can transport
1700/40 = 42.5 ft³ of soil per trip.
she would then earn
42.5 × 1.5 = $63.75 per trip.