from the quetion, we were told that:
The retired police officer has two children and five grand children.
He leaves $135,000
lets divide the $135,000 that he leaves in 7 persons. Recall that each child gets double of what a granchild gets.
Let the amount of child br $x and that of grand children be $y and let us set two equations in x and y and then solve them together for x and y.
A chid amount = 2(grandchild amount).
x = 2y
And sum of 2 children + sum of 5 grandchildren = 135,000
2x + 5y = 135000
2(2y) + 5y = 135000
4y + 5y = 13500
9y = 135000
divivide both sides by 9
9y /9 = 135000/9
y = 135000/9
y = 15000
So, each grandchild gets $15000.
And accordingly child gets 2(15000) = $30000
That is, each grandchild gets $15000 and child gets $30000