**Question 17**:

**Solving using matrix method is not allowed in this question.**

Diagram shows a rectangular fish pond with the perimeter of 62 m.

It is given that the length of the fish pond is 3 times its width.

Calculate the length, in m, of the fish pond.

**Given**

*Solution:*

*y*+ 4 = 3

*x*

*y*= 3

*x –*4 …………. (1)

Perimeter = 62

2

*x*+ 2(

*y*+ 4) = 62

2

*x*+ 2

*y*+ 8 = 62

2

*x*+ 2

*y*= 54

(÷2)

*x*+

*y*= 27 …………. (2)

Substitute (1) into (2):

*x*+ 3

*x –*4 = 27

4

*x –*4 = 27

4

*x*= 27 + 4

4

*x*= 31

*x*= 7.75

From (1):

*y*= 3

*x –*4

When

*x*= 7.75

*y*= 3(7.75)

*–*4

*y*= 19.25

Length of the fish pond

=

*y*+ 4

= 19.25 + 4

=

**23.25 m**

**Question 18**:

Solution by matrix method is

**not**allowed to answer this question.

Diagram shows a bicycle and a tricycle.

Calculate the number of bicycles and the number of tricycles if there are 64 pedals and 74 tyres.

**Let bicycle =**

*Solution:*

*x*and tricycle =

*y*

So,

2

*x*+ 2

*y*= 64 …………. (1)

2

*x*+ 3

*y*= 74 …………. (2)

(2) – (1)

3

*y*– 2

*y*= 74 – 64

*y*= 10

When

*y*= 10

From (2)

2

*x*+ 3(10) = 74

2

*x*= 74

*–*30

2

*x*= 44

*x*= 22

Thus, the number of bicycles are 22 and the number of tricycles are 10.