For the first question, we can use the distance = rate * time formula.
Plug in the appropriate values. We know the distance is 10 miles and he took 55 minutes. We should convert the 55 minutes to hours because we would like to work in miles per hour.
55/60
Simplify
55/60 = 11/12
10 = 11/12 * r
Divide both sides by 11/12
r ≈ 10.9090909091
Round to the nearest hundredth.
r = 10.91
Now for the second question.
Move the % sign two places to the left and make it into a decimal point.
48.5% = 4.85
Now for the last question.
Convert the percent into a decimal. To do this, move the % sign two places to the left and make it into a decimal point.
15% = 0.15
And if only 18 students have an "A" that means there are x students. 0.15 of x will yield 18. So, we need to figure out what x is.
0.15 * x = 18
Divide both sides by 0.15
x = 120
So, 120 students are in Mrs. Madison's math class.
