Question

Three quarter of the students running a 100-yard race finished with an average time of 16 seconds. The remaining 25% of students finished with an average time of 12 seconds. What was the average time overall?

Answer 1

15 seconds

Explanation:

Because the split id 25% and 75%, we could create another average pretending that there are four kids, one who ran in 12 seconds, and three who ran in 16.

Equation for averages: (a₁ + a₂ + a₃ + ...
`a_(n)`)/ n

Plug in: (12 + 16 + 16 + 16)/4

Add: 60/4

Divide: 15 seconds