Question

you and a friend have a hula hoop competition. you win 3 out of every 7 trials. your friend wins 5 more trials than you. how many trials are in the competition?

Answer 1

12 or 13. See below Use 12 first then 13

Explanation:

Write the proportion

3:7 = x:(x + 5) Write the proportion in fractional form.

3/7 = x / (x + 5) Cross multiply

3*(x + 5) = 7x Remove the brackets

3x + 15 = 7x Subtract three x from both sides.

3x - 3x + 15 = 7x - 3x Collect like terms

15 = 4x Divide both sides by 4

15/4 = 4x/4 Divide

3.75 = x The question is when to round and how.

The total number of competitions was x + x + 5 = 2x + 5

total = 2*3.75 + 5

total = 7.5 + 5

Total = 12.5 which I would round to 12. If that does not work, use 13. You round at the end.