Question: A frog pond has five frogs living in it. Some frogs laid eggs, and now there are three times as many tadpoles growing into more frogs as there are frogs. Two-thirds of the tadpoles will survive to maturity as frogs. The pond can only sustain eight frogs. How many frogs will have to find a new pond when the tadpoles grow up? Think carefully first, then make a decision:
There are three times the number of tadpoles as frogs, so there are 3 * 5 = 15 tadpoles. Two - thirds of the tadpoles will survive to become frogs, so 2 * 15 / 3 = 10 tadpoles will grow into frogs. When the tadpoles grow up, there will be 5 + 10 = 15 frogs in the pond. The pond can only sustain 8 frogs, so 15 - 8 = 7 frogs will need to find a new pond. So the answer is 7.