Percentages

problem

Better Spelling

Age

11 to 14

Challenge level

Weekly Problem 12 - 2010
Can Emily increase her average test score to more than $80$%? Find out how many more tests she must take to do so.
problem

Trusting the Tabloids

Age

11 to 16

Challenge level

Can you match the cards and figure out whether the tabloid headlines can be trusted?
problem

Round and Round

Age

14 to 16

Challenge level

Prove that the shaded area of the semicircle is equal to the area of the inner circle.
problem

Antifreeze

Age

14 to 16

Challenge level

How much more antifreeze is needed to make the proportion 30%?
problem

Percentage Swap

Age

14 to 16

Challenge level

What is 50% of 2007 plus 2007% of 50?
problem

Margins

Age

11 to 14

Challenge level

Weekly Problem 16 - 2008
A 30cm x 40cm page of a book includes a 2cm margin on each side... What percentage of the page is occupied by the margins?
problem

Percentage Unchanged

Age

14 to 16

Challenge level

If the base of a rectangle is increased by 10% and the area is unchanged, by what percentage is the width decreased by ?
problem

Antiques Roadshow

Age

14 to 16

Challenge level

Last year, on the television programme Antiques Roadshow... work out the approximate profit.
problem

Slightly Outnumbered

Age

11 to 14

Challenge level

If this class contains between $45$% and $50$% girls, what is the smallest possible number of girls in the class?
problem

You Never Get a Six

Age

7 to 11

Challenge level

Charlie thinks that a six comes up less often than the other numbers on the dice. Have a look at the results of the test his class did to see if he was right.