Question

1/5 of J's money is equal to 1/3 of S's money. The difference in their amount is 1/2 of A's money. If Adam gives $120 to S, S will have the same amount of money as J. How much do the 3 people have altogether?(please show me a model method, not algebra)

Answer 1

1/5 J= 1/3 S
J-S=1/2 A

S+120=J

Well, looking at the last equations, it is obvious that J-S=120

then A=240

J-S=120
3J-5S=0 From first equation.

3J-3S=360
3J-5S=0
2S=360
S=180
finally, J=300

Sum them up.