Tables and graphs

Exercise 1

Marianne goes shopping with her friend Anneke. They pass a store with great bargains. They quickly enter.

a

Marianne sees a sweater for € 49.98. What will this sweater cost after the discount?

b

Anneke buys two pairs of jeans with a pricetag of € 51.75. What does she pay for them?

c

Marianne sees a blouse with a discount of 20%. The shop price is € 33.50 and she has to pay € 27.00 for it. Is the discount percentage correct?

Exercise 2

You have deposited an amount of € 1000 into a bank account on 1 January 2009. You leave the money untouched and receive a yearly interest of $3.5$ %.

a

How much money is in your account on $1$ January 2010?

b

And how much on 1 January 2011?

c

Is the amount of interest the same every year? Why?

Exercise 3

You get a 40% discount on a stereo set. You do need to pay 21% sales tax, however. There are two possibilities:

The shop owner first computes the discounted price and then adds the sales tax.
The shop owner first adds the sales tax to the price and then takes of the $40$ % discount.

Use a computation to show which is the most profitable for you and what the difference is.

Exercise 4

You can buy a € 295 leather desk chair for € 200.
What is the discount percentage?

Exercise 5

A $250$ gram box of chocolate sprinkles costs € 1.75. The producer has the following offer: 20% more for the same price.

What is your discount?

Exercise 6

The water of the river Rhine flows into different river branches when it enters The Netherlands.
First 65% enters the river Waal and 35% enters the Nederrijn. Just before Arnhem the Nederrijn then splits again. There 60% of the water flows into the river Lek en 40% into the river IJssel.

a

What percentage of the Rhine's water flows into the Ijssel?

b

What percentage of the Rhine's water flows into the North Sea via the Lek?

c

The Rhine's water becomes polluted in the Ruhr area by the discharge of a certain amount of coloring agents. Researchers estimate that $640$ kg of those coloring agents end up in the IJssel. How many kilograms of coloring agents were discharged?

Exercise 7

The table contains information about the population and surface area of the Indonesian archipel in 1980. Some numbers are missing.

a

What is the total number of inhabitants of Indonesia in 1980? Give the number in millions.

b

How big was the total surface area of all Indonesian islands combined?

c

Compute the numbers that are missing in the table.

d

The population density is the number of people per km². Which island has the largest population density?

e

Compute the population density of the whole of Indonesia.

Exercises