Johnny bought six peanut butter cans at an average price (arithmetic mean) of 35¢.
Johnny bought six peanut butter cans at an average price (arithmetic mean) of 35¢. If Johnny returned two cans to the retailer, and the average price of the remaining cans was 31¢, then what is the average price, in cents, of the two returned peanut butter cans?
Answer/Solution
43
Steps/Work
Total price of six cans = 6*35 = 210
Total price of 4 cans = 4*31 = 124
Total rice of two cans = 210 - 124 = 86
Average price of two cans = 86/2 = 43 c
Another way to do it is this:
Assume that the four leftover cans were of 31c each. The avg was 35c initially because the two cans were 35c each and were providing another 4c of cost to other 4 cans.
So cost of the two cans = 2*35 + 4*4 = 86
Avg cost of the two cans = 86/2 = 43c
Answer (B)
Total price of 4 cans = 4*31 = 124
Total rice of two cans = 210 - 124 = 86
Average price of two cans = 86/2 = 43 c
Another way to do it is this:
Assume that the four leftover cans were of 31c each. The avg was 35c initially because the two cans were 35c each and were providing another 4c of cost to other 4 cans.
So cost of the two cans = 2*35 + 4*4 = 86
Avg cost of the two cans = 86/2 = 43c
Answer (B)