Multiple choice

Three children each weigh less than or equal to 100 pounds. Their average weight is 70 pounds. If one of them weighs 80 pounds, what is the least possible weight, in pounds, of a child in the group?

  1. 25

  2. 30

  3. 50

  4. 60

  5. 80
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sum of 3 weights = 3 * 70 = 210. One is 80, so the other two sum to 130. To minimize one, maximize the other. The maximum weight is 100. So, 130 - 100 = 30.

AI explanation

Using the properties of average, the total weight of the three children is 70 multiplied by 3, which equals 210 pounds. To find the least possible weight of one child, the other two children must weigh their maximum possible weights, which is 100 pounds and the given 80 pounds. The sum of these two weights is 180 pounds. We subtract this from the total weight to find the minimum weight, so 210 minus 180 equals 30 pounds.

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