Section: Mathematical Reasoning

34) Alter working 3 hours, Mary has made 31 cogs. At the same rate, how many cogs can she make in a 40 hours?

1. 40(3) /31
2. 3(31) / 40
3. 40(31)
4. 40(31) / 3
5. (3)(31)

Let x = number of cogs Mary can make in 3 hr.


Set up a proportion:

3 / 31 = 40 / x

3x = 40(311)

x = 40(31) / 3