A ratio shows the relationships between amounts that make up a total quantity.

A ratio is written in the form **part : part** - both numbers in the ratio are part of the whole.

Ratios may consist of more than 2 numbers and is shown with additional parts eg 2:3:5.

A packet of sweets contains two flavours: there are strawberry sweets and banana sweets. If there are 64 sweets in the packet, and 40 of the sweets are banana flavour, what is the ratio of strawberry to banana sweets?

Number of strawberry sweet = 64 - 40 = 24

The ratio is 24:40.

This simplifies to 3:5 (divide both parts by 8).

Note that the numbers have to be in that order.

Answer: 3:5

A mix of concrete weights 48kg. It is known that 12kg is cement and that the rest was sand. What is the cement:sand ratio?

The amount of sand was 48 - 12 = 36kg.

The mix was therefore 12:36, which simplifies to 1:3.

Answer: 1:3

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