# Proportional Problems

## Simple Proportion

If something is in proportion to something else, it means that there is a link between the two things. For example, a ratio is in proportion as the two numbers are linked. Look at the example on the right to get started. There are 10 photos on one CD. The question is? How many photos are there on 4 CDs. To find the answer, we have to multiply the photos on one CD (10) by 4 as there are four CDs. This then gives us 40. There are 40 photos an 4 CDs. Solving Proportional Problems using the Unitary Method The unitary method is a method in which we find the value for 1 unit (eg: the price of one bread, the weight of one camel, etc.) to solve more complicated proportional problems. There are two examples underneath which explain how the unitary method is applied in different situations. Browse our Topics Go to our library to browse more interesting topics on our website. Please share this page if you like it or found it helpful!
Example 1 There are 240 bananas in 8 boxes. How many bananas are there in one box? 8 boxes > 240 bananas 1 box > ? bananas 240÷8 = ? = 30 1 box > 30 bananas. There are 30 bananas in one box. We have found this solution b dividing the number of bananas by the number of boxes. This is basically the reverse of what we have done in the example above.

### 40 Photos

1 CD
4 CDs
Example 2 There are 84 people in 21 cars. How many people are there in one car? 21 cars > 84 people 1 car > ? people 84÷21 = ? = 4 1 car > 4 people There are 4 people in one car. We have found this solution using the same method as in the example above.
Example 1 There are 140 breads sold in 7 hours. How many breads are sold in 9 hours? 7 hours > 140 breads 9 hours > ? breads 140÷7 = 20 1 hour > 20 breads 20×9 = 180 9 hours > 180 breads 180 breads are sold in 9 hours. We have solved this problem by finding out how many breads are sold in 1 hour and then multiplying this value by 9. This is the unitary method in action.
Example 2 A lift can transport 75 tourists in 3 rides. How many tourist can be transported in 100 rides? 3 rides > 75 tourists 100 rides > ? tourists 75÷3 = 25 1 ride > 25 tourists 25×100 = 2500 100 rides > 2500 tourists 2500 tourists can be transported in 100 rides. We have solved this problem using the unitary method (by finding how many tourists are transported in 1 ride.) We then multiplied this value by 100 to find how many were transported in 100 rides.
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