各位知識朋友 , 入黎幫我手 ar !!! ( 數學F.1 ) (42)

Let X be the age of Sophia.
Sophia is X years old.
Dick is (X+28) years old.
Gary is (X*1/4) years old.
Maria is [(X*1/4)+18] years old.
Given that Maria is 28 years old.
So there is an equation
(X*1/4)+18=28
(X*1/4)=28-18
X =40
Since Sophia is X years old,
so Sophia is 40 years old.
So the age of Dick = 40+28
= 68
Dick is 68 years old.

Let x be age of Gary,
let y be age of Sophia and
let z be age of Dick.

Maria is 18 years older than Gary, so that
28=x+18
x=10

Gary is 1/4 the age of Sophia, so that
10=1/4(y)
y=40

Sophia is 28 years younger than Dick, so that
40+28=z
z=68

*So Dick is 68 years old

Gary=28-18=10years old

Sophia=10÷1/4=40years old

Dick=40+28=68years old!