# FREE OLNA Numeracy Questions and Answers

#### Vera is building a house. She estimates her main costs to be:

Buying land: $215 000

Planning approval: $4685

Cost of building: $197 500

To the nearest $1000, what is her total cost?

Explanation:

Adding all four amounts together will give Vera a total of $417 185.
Rounding to the nearest thousand means:

We go up to the next thousand if the number in the hundreds place is five or more.

Because the number in the hundreds place is one, we leave the thousands number (7) as it is.

#### Baby John weighed 3100 grams at birth. It is estimated that in the next 12 months, his weight will increase threefold.

What will John’s estimated weight be in 12 months?

Explanation:

Times means multiply. Therefore 3100 x 3 = 9300 grams.

9300 is not one of the choices, so we need to change 9300 grams to kilograms.

The fact that 1000 grams = 1 kilogram, means 9300 grams = 9.3 kilograms.

#### A shopping centre car park has 900-car parking bays divided into three sections.

Section 1 has 480 bays, and section 2 has half as much as Section 1.

The remaining bays are in section 3.

How many bays are there in Section 3?

Explanation:

There are 900 car bays in the car park.

Section two has 240 car bays (half of 480).

Section three will equal 900 – 480 – 240 = 180 car bays.

#### A car’s petrol tank is three-quarters full. The motorist topped up the tank by adding 12 litres. How many litres does the tank hold when full?

Explanation:

The fuel tank is ¾ full. The motorist has to add fuel to the remaining ¼ of a tank.

The motorist adds 12 litres of fuel to fill the remaining ¼ of a tank.

This means ½ a fuel tank is worth 24 litres, so a full tank must be 48 litres.

#### A map has a scale of 1 centimetre representing a distance of 2 kilometres in real life.

What is the appropriate scale for the map?

Explanation:

1 cm:2 km means 1 cm:200 000 cm as there are 100,000 centimetres in a kilometre.

#### A wheat silo receives grain at a rate of 15 tonnes per minute. How long will it take the silo to receive 120 tonnes of grain?

Explanation:

Fifteen tonnes per minute is the rate.

To find the number of minutes it takes to receive 120 tonnes, we divide 120 by 15.

120 ÷ 15 = 8

#### Joseph wants to buy a pair of runners. He visits five stores and notes the prices on offer for the same style of shoe.

The prices are listed as: $59, $58, $58, $64 and $66.

What is the mean (average) price of the shoes?

Explanation:

The mean is found by adding all scores and dividing by the number of scores.

The five scores add to 305. Hence the mean is 61 ($305 ÷ 5 = $61).

#### In a jar of 20 marbles, there are orange, purple, and red marbles. A marble is chosen at random from the jar. Eli wants either an orange or a purple marble.

What is the probability of Eli getting what he wants?

Explanation:

The probability of an event happening is: What you want divided by the total number of outcomes.

In the jar, there are eight red, three orange, and nine purple marbles. The total number of marbles is 20.

Eli wants an orange or purple marble, of which there are 12.

#### A nanosecond is one billionth of a second.

Which of the following is a nanosecond?

Explanation:

One billion is one thousand million or 1 000 000 000.

So, therefore, one billionth is one over a billion.

#### Tina is t years old. Lisa is 6 years older than Tina. Together their ages total 26.

Which equation represents the girls’ age structure?

Explanation:

If Tina is t years old, then Lisa must be t + 6, not 6t (this is times).

Now add the ages together t + t + 6 = 2t + 6.

2t + 6 = 26

#### The goals scored by players during a soccer season are graphed below.

Which player scored six goals less than Sam?

Explanation:

Studying the columns closely, we notice Sam has scored 18 goals.

Six less than 18 is 12 (18 – 6). So, we need the column showing 12 goals.

By observation, we notice that Fred is the player that has scored 12 goals.