Question

There are two plants. The first plant is 5 cm tall and grows 2.5 cm each day. The second plant is 3 cm tall and grows 6 cm each day. In how many days the second plant be double the height of the first plant

Answer 1

Answer:

         7 days

Step-by-step explanation:

After d days, the height of the first plant (in cm) will be

     h₁ = 5 + 2.5d

and the height of the second plant (in cm) will be

     h₂ = 3 + 6d.

So the height of the second plant is double the height of the first...

     ⇒  h₂  =  2h₁

     ⇒  3 + 6d  =  2 ( 5 + 2.5d )

     ⇒  3 + 6d  =  10 + 5d

     ⇒  d = 7.

So this happens after 7 days.

Hope this helps!