Mr Kim gave $3600 to his wife and two children altogether. His wife received $500 more than his son. His son received twice as much as his daughter. How much did Mr Lim's wife received?

w+s+d = 3600

w = s+500, so s = w-500
s = 2d, so d = s/2 = w/2 - 250
Now just solve for w.
w + (w-500) + (w/2 - 250) = 3600
5w/2 = 4350
w = 2/5 * 4350 = 1740

check: 1740 + 1240 + 620 = 3600