So this one is 2.2 inches long now and growing at a constant rate of 0.2 inch a day. We need to find how many days it will take until the vine grows to 11.2 inches.
We will first subtract 2.2 inches from 11.2 inches because we already have 2.2 inches, otherwise, we'd be finding how long it'll take to grow another 11.2 inches.
11.2 inches - 2.2 inches = 9 inches
The vine needs to grow another 9 inches.
We can find out how many days it will take the vine to grow 9 inches by diving the height needed by the rate it is growing. So that'll be 9 inches divided by 0.2 inch/day.
9 inches / 0.2 inch/day = 45 days.
In 45 days the vine will be 11.2 inches long.