Jennifer had a total of 132 markers and crayons. After she gave away 4/5 of
markers and 18 crayons, she had an equal number of markers and
crayons left.
(a) How many markers did she have left?
(b) How many crayons did she have at first?
In this question, concept of solution of simultaneous equation is applied.
Let, x be number of markers and y
be number of crayons.
According to question,
x + y = 132 (1)
She have equal number of markers and crayons left, when she gave away 4/5 of markers and 18 crayons.
x - 4/5x = y - 18
x/5 = y - 18
x = 5y - 90
5y - x = 90 (2)
Solving (1) and (2)
x + y + 5y - x = 132 + 90
6y = 222
y = 222 ÷ 6 = 37
Put y = 37 in (1)
x = 132 - 37 = 95
a)
Firstly she had 95 markers.After giving 4/5 of markers, she had
95 - 4/5 × 95 = 19 markers.
b)
She had 37 crayons at first.