Answer:$20
Explanation:
The total money paid
$105 + $125 + $175 = $405
If they are to share the cost equally, then each are to pay $405 ÷ 3 =$135 each
Since tom paid $105, He need to give out $30 more to make it $135, so he will give sam $30
Since Dorothy initially Paid $125, he will need to give out $10 to make his total pay $135, so he gave sam $10
Therefore $t = 30 and $d=10
$t -$d = $30 - $10 = $20