The numbers you are multiplying would be smaller and hence the multiplication calculations would be simplified. This will be especially pertinent when you are doing calculus or algebra and you need to multiply different polynomials. Dividing out common factors is also common in some maths questions to derive the final answer or to prove an equation.
The equation for this would be:

. first you want to multiply 60 by 220, then divide the product by 165. 60 times 220 is 13,200. Now divide 13,200 by 165. This will give you 80. Todd has to eat 80 grams of protein each day to stay healthy.
3/4 / 2/1
Keep, Change, Flip
3/4 * 1/2 = 3/8
5/4 / 2/1
Keep, Change, Flip
5/4 * 1/2 = 5/8
Answer: 3/8 and 5/8
18 plants i think is the answer