Problem of the Week - Upper Elementary - Oct. 4, 2020 to Oct. 10, 2020

Upper Elementary:

Question: A frog eats half of the flies around a pond. A toad eats a third of the remaining flies. What fractional part of the flies are left at the pond? 

Answer:  ¹/₃ of the flies

Solution:  After the frog eats half of the flies, the other half of the flies are left. The toad therefore eats a third of a half of the flies, and a third of a half is a sixth. Since ¹/₂ + ¹/₆ = ²/₃, that means ¹/₃ of the flies are left at the pond.