Question

Bo and Erica are yoga instructors. Between the two of them, they teach 44 yoga classes each week. If Erica teaches 13 fewer than twice as many as Bo, how many classes does each instructor teach per week?

A. 23 Bo; 21 Erica
B. 21 Bo; 23 Erica
C. 16 Bo; 28 Erica
D. 19 Bo; 25 Erica

Answer 1

Answer: D. 19 Bo; 25 Erica

Explanation:

Let x represent the number of yoga classes that Bo teaches in a week.

Let y represent the number of yoga classes that Erica teaches in a week.

Between the two of them, they teach 44 yoga classes each week. This means that

x + y = 44 - - - - - - - - - - -1

If Erica teaches 13 fewer than twice as many as Bo, it means that

y = 2x - 13

Substituting y = 2x - 13 into equation 1, it becomes

x + 2x - 13 = 44

3x = 44 + 13 = 57

x = 57/3 = 19

y = 2x - 13 = 2 × 19 - 13

y = 25