If you add it all together it comes out to -
$16.83
6.19
4.25
2.39
=
12.83
1.50
1.50
1.50
1.50
=
16.83
But the question is how much did all of them spend so we gotta subtract
So
25+25+25+25= $1.00
24+24+24+24= $.96
23+23+23+23= $.86
22+22+22+22= $.88
21+21+21+21= $.84
2+2+2+2= $8.00
3+3+3+3= $12.00
4+4+4+4= $16.00
So rounding it equals they equally spent $4.21
