She worked 7.5 hours a day on average. You can get this by dividing the 37.5 by 5.
And the average she made was 118.13 when rounded. You can get this by multiplying the 7.5 by the rate
Nathaniel's total cost is $(3.50 x2 + 3.25 x4 +1.90 x2 +1.20) = $24 he got 5% off so he paid $24- (24* 5/100) =$22.80

now, there are 1000 grams in one Kilogram, so in 1680 grams, there are 1680/1000 Kilograms, namely 1.680.
20 and 0 are your answers