We can treat this like an equation.
We know the rate per month (1 2/5) and the end result (10 2/3).
X is the number of months, bc we don’t know how LONG it’s gonna take.
So 1 2/5 * x = 10 2/3
Now to solve this we have to first change the numbers to improper fractions. 1 2/5 becomes 7/5 and 10 2/3 becomes 32/3.
So now, 7/5 x = 32/3
To figure out what x is we have to isolate it. To do that when it’s connected to a fraction, we have to multiply both sides by the reciprocal of that fraction, which is 5/7. That cancels out the fraction.
So now, x = 160/21
Simplified that means x = 7 13/21
So it’s going to take the plant 7 13/21 months to grow a full 10 2/3.
This looks like a weird number, but my math looks right, so if I’m wrong correct me but hope this helps.