David, Evan and Filip go out and buy a computer game. They agree to share the cost equally. Filip only has $4.50 with him. David and Evan agree to pay the rest of Filip' share and he will pay them back. David pays in total 50% more than Evan pays in total. David pays $8.40 more than Evan. How much money does Filip need to pay back to David and Evan?

Guest Apr 23, 2022

#1**0 **

David, Evan and Filip go out and buy a computer game. They agree to share the cost equally. Filip only has $4.50 with him. David and Evan agree to pay the rest of Filip' share and he will pay them back. David pays in total 50% more than Evan pays in total. David pays $8.40 more than Evan. How much money does Filip need to pay back to David and Evan?

This one is a little sticky !!!!!

David pays 8.40 more than Evan....so....

D = E + 8.40 (1)

And David pays 50% more than Evan

D = (1.5)E (2)

Sub (2) into (1) and we have that

(1.5)E = E + 8.40

(1.5 -1) E = 8.40

.5E = 8.40

E = 8.40 / .5 = 16.80 = what Evan paid

And David paid 16.80 + 8.40 = 25.20

So.....the total cost paid =

What Evan paid + What David paid + What Filip paid =

16.80 + 25.20 + 4.50 = 46.50

Each should pay 46.50 / 3 = 15.50

So Filip owes Evan (16.80 - 15.50) = 1.30

And Filip owes David ( 25.20 - 15.50) = 9.70

Check

Filip has 4.50 + 1.30 + 9.70 = 15.50 which is his correct share

CPhill Apr 23, 2022