(a) Mr. Smith divides a sum of money between his three children
Alex, Billy and Charlie in the ratio 3 : 2 : 7. If Charlie received
$120 more than Alex, how much money did Billy receive?
Let x be the amount each receives.
i.e. Alex receives three times of x and Charlie 7 times.
7x-140=3x
7x-3x=140
4x=140
x=140/4
x=35
Billy receives two times of 2.
Therefore, he receives 35*2=$70.