**A ratio is an ordered pair of numbers a and b, written a / b where b does not equal 0. A proportion is an equation in which two ratios are set equal to each other. **

*A sum of money is to be distributed among A, B, C, D in the proportion of 5 : 2 : 4 : 3. If C gets Rs. 1000 more than D, what is B’s share?*

let the shares of A, B, C and D be Rs. 5*x*, Rs. 2*x*, Rs. 4*x* and Rs. 3*x* respectively.

Then, 4*x* – 3*x* = 1000

** B’s share = Rs. 2x = Rs. (2 x 1000) = Rs. 2000**

**Example 1:**

In a bag of red and green mint sweets, the ratio of red mint sweets to green sweets is 3:4. If the bag contains 120 green mint sweets, how many red mint sweets are there?

**Solution:**

Let *x* = number of red sweets.

**Write the items in the ratio as a fraction.**

3 × 120 = 4 × *x*

360 = 4*x*

**Answer: There are 90 red sweets.**

Clothing store A sells T-shirts in only three colors: red, blue and green. The colors are in the ratio of 3 to 4 to 5. If the store has 20 blue T-shirts, how many T-shirts does it have altogether?

**Let x = number of red shirts**and

*y*= number of green shirts

Write the items in the ratios as fractions.

3 × 20 = *x* × 4

60 = 4*x**x* = 15

5 × 20 = *y* × 4

100 = 4*y**y* = 25

The total number of shirts would be 15 + 25 + 20 = 60

Answer: There are 60 shirts.