A plant grows at a rate of 3cm per week. If the pant was already 4cm tall, how long until the plant is 13cm tall?

It would take 3 weeks for the plant to reach 13cm tall.

explanation:

The plant is grows at a rate of 3cm per week, and it’s already 4cm tall. so, in one week it would be 7cm tall, in two weeks it would be 10cm tall, and in three weeks it would be 13cm tall.