Joe had $475 more than Nigel at first. After Nigel spent 60% of his money and Joe spent 85% of his money to buy a present together for their friend, they were left with an equal sum of money. How much did the present cost?
Let Nigel's money ==N
Joe's money ==475 + N
N - 0.60N ==0.40N - what Nigel has left
0.15 * [475 + N]==71.25 + 0.15N - what Joe has left
0.40N ==71.25 + 0.15N, solve for N
0.40N - 0.15N ==71.25
0.25N ==71.25
N ==71.25 /0.25 ==$285 - what Nigel started with
$285 + $475 ==$760 - what Joe started with.
Nigel spent: 285 x 0.60 ==$171 - money spent to buy a present.
Joe spent ==760 x 0.85==$646 - money spent to buy a present.
[285 - 171] ==[760 -646]
$ 114 == $114 - what both had left at the end.
+237 Nigel have x money at first. Then Joe have (x + 475) money at first.
x - 60%x = x + 475 - (x + 475) * 85%
0.4x = x + 475 - 0.85x - 403.75
0.4x = 0.15x + 71.25
0.25x = 71.25
x = 285
x + 475 = $760.
285 * 60% + 760 * 85% = $817
The present cost $817
