Question

The sum of two rational numbers is `9/20`. If one of them is `2/5`, find the other. 

Answer 1

The sum of two rational number = `9/20`

And, one of the numbers = `2/5`

The other rational number

`= 9/20 - 2/5`

2	20, 5
2	10, 5
5	5, 5
	1, 1

LCM of 20 and 5 = 20

`= (9xx1)/(20xx1) - (2xx4)/(5xx4)`

LCM of 20 and 5 = 20

`= 9/20 - 8/20`

`= (9-8)/20 = 1/20`