Multiple choice

If the average (arithmetic mean) of the numbers k, k + 4, 2k - 3, 5k, and 3k + 1 is 10, what is the value of k?

  1. 2

  2. 3

  3. 4

  4. 5

  5. 6
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sum of (k + k+4 + 2k-3 + 5k + 3k+1) = 12k + 2. Average = (12k + 2) / 5 = 10. Thus, 12k + 2 = 50, 12k = 48, k = 4.

AI explanation

First, sum the five expressions: k + (k + 4) + (2k - 3) + 5k + (3k + 1) = 12k + 2. According to the average formula, divide this sum by 5 and set it equal to 10, giving (12k + 2) / 5 = 10. Solving this equation yields 12k + 2 = 50, so 12k = 48 and k equals 4.

Keep practicing — related questions