Math Repository
about
topic
al
year
ly
Yearly
2007
P2 Q1
Topical
Equations
07 P2 Q1
2007 H2 Mathematics Paper 2 Question 1
Equations and Inequalities
Answers
$
7.65
{\$7.65}
$7.65
Full solutions
Let
x
,
y
{x,y}
x
,
y
and
z
{z}
z
denote the price per kilogram of pineapples, mangoes and lychees respectively
1.15
x
+
0.6
y
+
0.55
=
8.28
z
1.2
x
+
0.45
y
+
0.3
=
6.84
z
2.15
x
+
0.9
y
+
0.65
=
13.05
z
\begin{align} && \quad 1.15 x + 0.6 y + 0.55 &= 8.28 z \\ && \quad 1.2 x + 0.45 y + 0.3 &= 6.84 z \\ && \quad 2.15 x + 0.9 y + 0.65 &= 13.05 z \\ \end{align}
1.15
x
+
0.6
y
+
0.55
1.2
x
+
0.45
y
+
0.3
2.15
x
+
0.9
y
+
0.65
=
8.28
z
=
6.84
z
=
13.05
z
Solving
(
1
)
,
(
2
)
{(1), (2)}
(
1
)
,
(
2
)
and
(
3
)
{(3)}
(
3
)
with a GC,
x
=
3.50
,
y
=
2.60
,
z
=
4.90
x=3.50, \; y =2.60, \; z = 4.90
x
=
3.50
,
y
=
2.60
,
z
=
4.90
Total amount Lee Lian paid
=
1.3
(
3.50
)
+
0.25
(
2.60
)
+
0.5
(
4.90
)
=
$
7.65
■
\begin{align*} & \textrm{Total amount Lee Lian paid} \\ & = 1.3(3.50) + 0.25(2.60) + 0.5(4.90) \\ & = \$7.65 \; \blacksquare \end{align*}
Total amount Lee Lian paid
=
1.3
(
3.50
)
+
0.25
(
2.60
)
+
0.5
(
4.90
)
=
$7.65
■
Back to top ▲