The average height of a jackfruit tree, a coconut tree and a mangosteen tree is 8.8 m. The mangosteen tree is thrice as tall as the coconut tree and 1.6 m taller than the jackfruit tree. Find the average height of the jackfruit tree and the coconut tree.
Total height of the jackfruit tree, the coconut tree and the mangosteen tree
= 3 x 8.8
= 26.4 m

Height of the coconut tree = 1 u
Height of the mangosteen tree = 3 u
Height of the jackfruit tree = 3 u - 1.6

Total height of the jackfruit tree, the coconut tree and the mangosteen tree
= 1 u + 3 u + 3 u - 1.6
= 7 u - 1.6

7 u - 1.6 = 26.4
7 u = 26.4 + 1.6
7 u = 28

1 u = 28 ÷ 7 = 4

Total height of the jackfruit tree and the coconut tree
= 1 u + 3 u - 1.6
= 4 u - 1.6
= 4 x 4 - 1.6
= 16 - 1.6
= 14.4 m

Average height of the jackfruit tree and the coconut tree
= 14.4 ÷ 2
= 7.2 m

Answer(s): 7.2 m