New Zealand
Level 6 - NCEA Level 1

# Modelling Linear Relationships - graphs

## Interactive practice questions

Petrol costs a certain amount per litre. The table shows the cost of various amounts of petrol.

 Number of litres ($x$x) Cost of petrol ($y$y) $0$0 $10$10 $20$20 $30$30 $40$40 $0$0 $16.40$16.40 $32.80$32.80 $49.20$49.20 $65.60$65.60
a

Write an equation linking the number of litres of petrol pumped ($x$x) and the cost of the petrol ($y$y).

b

How much does petrol cost per litre?

c

How much would $47$47 litres of petrol cost at this unit price?

d

In the equation, $y=1.64x$y=1.64x, what does $1.64$1.64 represent?

The unit rate of cost of petrol per litre.

A

The number of litres of petrol pumped.

B

The total cost of petrol pumped.

C

The unit rate of cost of petrol per litre.

A

The number of litres of petrol pumped.

B

The total cost of petrol pumped.

C
Easy
Approx 4 minutes

A diver starts at the surface of the water and begins to descend below the surface at a constant rate. The table shows the depth of the diver over $5$5 minutes.

There are $20$20 litres of water in a rainwater tank. It rains for a period of 24 hours and during this time, the tank fills up at a rate of $8$8 Litres per hour.

A baseball is thrown vertically upward by a baseball player when he is standing on the ground, and the velocity of the baseball $V$V (in feet per second) after $T$T seconds is given by $V=120-32T$V=12032T.

### Outcomes

#### NA6-5

Form and solve linear equations and inequations, quadratic and simple exponential equations, and simultaneous equations with two unknowns

#### 91027

Apply algebraic procedures in solving problems