-- As time goes on, the population gets bigger.
That's increasing.
-- If the same amount was ADDED to the population every 5 weeks,
that would be linear. But that's not what's happening here.
Every 5 weeks, the population is MULTIPLIED by the same amount (10).
That's increasing exponentially.
On a graph, it would be a curve, that not only gets higher as time
goes on, but also gets steeper (rising faster, increasing slope).