GMAT Practice Question: Beth has a collection of 8 boxes of clothing for a charity, and the average (arithmetic mean)...
Question
Beth has a collection of 8 boxes of clothing for a charity, and the average (arithmetic mean) number of pieces of clothing per box is c. If she replaces a box in the collection that contains 12 pieces of clothing with a box that contains 22 pieces of clothing, what is the average number of pieces of clothing per box for the new collection, in terms of c ?
- c-5/4
- c+5/4
- 8-10c
- 8+10c
- 8 c-10
Topics: mean, word problems, translations
Solution
Step 1
We start by defining a variable for the total number of pieces of clothing across all 8 boxes and translate the given average.
T = 8c
Step 2
We compute the new total after removing the 12-piece box and adding the 22-piece box.
T_new = T - 12 + 22
Step 3
We find the new average by dividing the updated total by 8 and then simplify the fraction.
T_new8 = 8c + 10/8 = c + 10/8 = c + 2524 = c + 5/4
Answer
B
