Question

James had $240 more than his
brother, Sam, at first. After their mother gave James $30 and Sam $50 James had twice as much money as Sam. How much money
did Sam have at first?

Answer 1

At first:
Sam had ---- x
James had --- x+240

after mother's charity:
Sam had x + 50
James had x+240 + 30 = x + 270

x + 270 = 2(x+50)
x + 270 = 2x + 100
-x = -170
x = 170

Sam had $170 and James had 410

check:
after mom: Sam had 170+50 = 220
james had 410 + 30 = 440 , which is twice what Sam had