Try this solution, note, the suggested option is not the shortest way.
What you want to do is make a common denominator (the bottom number)
So does 3 go into 12? Yes it does (3 x 4)
So since you times the 3 by 4 you have to times the 2 by 4 aswell (so that it stays the same number just on a diffrent scale) the 2/3 becomes 8/12 (which is also 2 thirds) so you do 7/12 + 8/12 (7 twelths plus 8 twelths) which becomes 15/12 (15 - 12 = 3
So it comes 1 3/12 or 1 1/4)
12*11=132 combinations.
So he can pick any of 12 players as the first captain and he can pick any of the 11 remaining players to be the second captain.
I think with the kinds of mixture problems, it's really helpful to make a table.
The equations you actually need are
and
. Since I was so close, I went ahead and just solved it anyway. You can see my setup on the attached image.
Answer:
Each board should be 2.15 ft long
Step-by-step explanation:
6.45 ft ÷ 3 boards = 2.15 ft for each board