Math
posted by Jenny .
Linda is 9/10 as tall as patrick and 3/4 as tall as Ali. If the total height of the 3 pupils is 418.5 cm, how much taller is Ali than Patrick? Please help me and tell me how you get the answer step by step. Thanks

Let the heights be L, P and A.
L + P + A = 418.5
L = (9/10) P (or P = 10/9 L)
L = (3/4) A (or A = 4/3
You now have three equations in three unknowns.
You can use the method of substitution to turn them into one equation in one unknown.
L (1 + 10/9 + 4/3) = (31/9)L = 418.5
L = 121.5 cm
P = 135 cm
A = 162 cm
A  P = 27 cm