Ratio and Proportion Flashcards
Understand different ways to use ratio
If one taxi can carry 4 passengers, how many passengers can 3 similar taxis carry?
The taxi and number of passengers are in direct proportion:
If 1 taxi can carry 4 people, then 3 taxis can carry 12 (3 times as many).
3x4 = 12
In a recipe for scones, you need 50g of butter to make 4 scones.
Q. How many grams of butter do you need to make 36 scones?
Remember: The amount of butter you need is directly proportional to the amount of scones you make.
Check your Answer
write down what you have:
50g makes 4 scones
?g makes 36 scones
Divide 36 by 4 to see how many times to multiply the number of grams of butter.
36 ÷ 4 = 9
Multiply 50g by 9 = 450g of butter
Check ( reverse calculation)
4x9 = 36
George has £1 and Mike has £3.
Q. Write the amount of money George has compared to Mike as a ratio.
A ratio is a way of comparing two or more quantities.
The ratio is 1 to 3 which is written as:
1 : 3
Simplify the ratio 15 : 60
You usually simplify ratios as far as you can.
To simplify a ratio, keep dividing until the ratio can’t be divided anymore.
15 : 60 5 will go into 15 and 60
÷ both sides by 5
3 : 12 3 will go into 3 and 12
÷ both sides by 3
1 : 4
Two friends set up a business together.
Jack invested £1500.
Brian invested £4500.
They share their profits in the same ratio as the money they invested.
Q. Write this ratio in the simplest form.
1500 : 4500
simplest form:
1 : 3
A hairdresser has to mix hair dye from a base colour and copper colour in the ratio 1 : 2
She mixes 27 ml of base colour with 9ml of the copper colour.
Q. Is she correct?
The order of the ratio is important.
she mixes dye from a base colour with a copper colour in the ratio 1:2. 1 part base colour to 2 parts copper.
1 : 2
27 : 9
She is incorrect she should add 54 ml (2x27)
