maths
posted by jo .
Amy had 20% more money than John. After she spent 50% of her money, she had $72 less than John. How much money had she left?

John has $X.
Amy had X + 0.2X = $1.2X.
1.2x/2 = x  72,
0.6x = x  72,
x  0.6x = 72,
0.4x = 72,
X = $180. = John's Amt.
X  72 = 180  72 = $108 = Amy,s bal.