Given that,
Total amount of money = $4200
A certain sum of money is to be shared in the ratio 1:3:2 for Jack, Kerry and Shane.
To find,
The difference between Jack and Kerry's share.
Solution,
Let Jack's, Kerry's and Shane's share is x, 3x and 2x.
ATQ,
x + 3x + 2x = 4200
6x = 4200
x = 700
Jack's share = x = $700
Kerry's share = 3x = 3(700) = $2100
Difference = Kerry's share - Jack's share
= 2100 - 700
= $1400
So, the required answer is $1400.