Problema Solution
Alex spent 3/7 of his money.He gave 1/4 of the remainder to his sister.
He had $120 left.How many did he have in the beginning?
Answer provided by our tutors
Lets say that Alex had total of 'x' money. We are looking for x.
He spent (3/7) * x of the money,
gave (1/4)(x - (3/7)x) = (1/4)*(4/7)*x = (1/7) * x to his sister
and was left with $120.
All of this can be written as:
(3/7)*x + (1/7) * x + 120 = x
(4/7)*x + 120 = x
x - (4/7)*x = 120
(3/7)*x = 120
x = (120*7)/3
x = 280
Alex had $280 in the beginning.