Multiple choice

At a Comic-Con charity drive, Maya has 10 crates of donated comics. The average (arithmetic mean) number of comics per crate is r. She swaps out one crate containing 15 comics for a new crate containing 25 comics. What is the new average, in terms of r?

  1. r

  2. r + 1 10

  3. r + 1

  4. r + 10

  5. r - 1
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Original total sum = 10r. New sum = 10r - 15 + 25 = 10r + 10. New average = (10r + 10) / 10 = r + 1.

AI explanation

The total number of comics Maya originally has is 10 times r, which equals 10r comics. When she swaps a crate of 15 comics for a crate of 25 comics, she adds 10 comics to the total, making the new total 10r plus 10. The new average is the new total divided by 10, which simplifies to r plus 1.

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