Inactive Tutor answered 03/29/18
Tutor
New to Wyzant
the quantity in parentheses is = 12/20 + 6/20 = 18/20 = 9/10.
The problem is the ratio of 7/4 to 9/10 and when one fraction is divided by another fraction, you invert the divisor and do multiplication: (7/4)(10/9) = 35/18.