In a supermarket, the first 25 customers of the day purchased an average of two items each. After a further 15 customers, the average number of items purchased by each customer rose to eight. What was the average number of items purchased by the last 15 customers only?
Your Answer:
Correct Answer: 18
15 + 25 is 40, then multiplied by 8 gives a total of 320. Take 25 times 2 (or 50) off that figure to get 270, then divide that by 15 to arrive at the final answer, 18.