Question

Rebecca has been planting young trees in her garden. The maple tree that is 10 centimeters tall

is growing 2 centimeters per month, whereas the oak tree that is 15 centimeters tall is
growing 1 centimeter per month. In a few months, the two trees will be the same height. How
many months will this take and what will that height be?

Answer 1

It will take 5 months and that height will be 20cm.

Explanation:

Let the height of the tree be h cm and the number of months be m.

Maple tree

Initial height= 10cm

Total height= 10cm +2(number of months)

h= 2m +10 -----(1)

Oak tree

Initial height= 15cm

Total height= 15cm +1(number of months)

h= m +15 -----(2)

When the height of the two trees are the same,

2m +10= m +15

Solve for m:

2m -m= 15 -10

m= 5

Substitute m=5 into either equation 1 or 2 to obtain the height.

When m=5,

h= 5 +15

h= 20