When a certain tree was first planted, it was 4 ft tall, and the height of the tree increased by a constant amount each year for 6 years. At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year?
Took x as constant increase. Afer 6 years, height is 4+6x
After 4 years, height is 4+4x
(4+4x)6/5 = 4+6x
D is my answer.
The path is long, but self-surrender makes it short;
the way is difficult, but perfect trust makes it easy.