Question

An ant went 2 meters away from its nest searching for food. The next time, the ant went 3 meters away. Each successive time the ant leaves the nest to search for food, the ant travels the sum of the two previous times. How far will the ant travel on his fifth trip?

Answer 1

Answer:

The first time, the ant went 2m away, then we have a₁ = 2m

The second time, the ant went 3m away, then we have a₂ = 3m

The next time, the ant went a distance equal to the sum of the two previous ones, so we can write it in a general case as:

aₙ = aₙ₋₁ + aₙ₋₂

Only if n > 2.

then the third time, we have n = 3.

a₃ = a₂ + a₁ = 2m + 3m = 5m

a₄ = a₃ + a₂ = 3m + 5m = 8m

a₅ = a₄ + a₃ = 5m + 8m = 13m

This means that in the fifth trip, the ant went 13 meters away from its nest.

And if we consider the fact that the ant must go and return, then it will move a total distance of 13 meters two times, or 2*13m = 26 meters.