3.24 + 5.70 + 6.17 = 15.11
20.00 - 15.11 = 5.11
He got 5.11$ of change back.
20miles increased by 30%=new mileage added
20x.3= 6
6 miles more than his previous distance so...
6+20= 26
NOTE you can also use 1.3 instead of .3 as the percent to get the answer with out addition.
Answer:
b. and d.
Step-by-step explanation:

25 were on the roller coaster.
Multiplication and subtraction
The first step in solving this problem is taking 2 and 3 and multiplying them (2 * 3 = 6) .
Now, for the second step, we will cube it. Since there are 2 numbers, we are going to use the 2nd root (2sqrt(6)) This will give us: 4.89897948557 or 5 if you would round it. This would be the Geometric Mean.