The average weight of 10 boys is 77.0 pounds. If the
youngest boy is excluded, the average weight of the
9 remaining boys is 78.0 pounds. What is the weight,
in pounds, of the youngest boy?

Respuesta :

Answer:

68 pounds.

Step-by-step explanation:

Find the total weight when there are 10 boys and when there are 9 boys then calculate the difference.

I'll let x = total weight.

[tex]\frac{x}{10}=77\\(10)\frac{x}{10}=77(10)\\x=770\\\\ \frac{x}{9}=78\\(9)\frac{x}{9}=78(9)\\x=702\\\\ 770-702=68[/tex]

Therefore, the youngest boy weighs 68 pounds.