Question

How quickly a leaf grows is proportional how big [ie the surface area] the leaf is. If the area of the leaf grows from 2cm^2 to 3cm^2 in 5 days, how long will it take for the leaf's area to increase to 5cm^2?

Answer 1

x=the time required, i.e. the time for the surface to reach 5 cm^2. According to the statement, the rate of growth is proportional to the surface,

(3cm²-2cm²) / 5 days = (5cm²-2cm²)/x

1/5=3/x

x=5*3

x=15

x = 15 days

It takes 15 days for the leaf's surface area to reach 5 cm^2, bearing in mind that the rate of growth is proportional to its size or surface area.