## Average

Average also is one of the topics which is being given some considerable weight age in the Scholarship Aptitude Test preparation and Competitive examinations.Problems on avg. will not be difficult to be solved if the students know some important formula and tricks.Students who are to develop their aptitude skills have to learn this topic.Questions are being asked in this topic in aptitude test which is commonly conducted by the software companies for the purpose of placement.

The main formula to be remembered:

This is the formula which is always applied to find avg.

Problems:

1.The avg. age of 30 children is 9 years. If the teacher’s age is included, the average age becomes 10 years. What will be the age of teacher?

Solution:

Avg. = Total age of 30 children/30

9 = Total age of 30 children/30

9x30= Total age of children

Total age of 30 children = 270

Avg. age of 30children + 1 teacher = (Total age of 30 children +1 teacher)/31

10 = (Total age of 30 children+1 teacher)/31

10x31 = Total age of 30 children + 1 teacher

310 = Total age of 30 children + 1 teacher

Total age of 30 children+1 teacher = 310

270+ Age of one Teacher = 310

Age of one Teacher = 310-270

Therefore, Age of one Teacher = 40

2. The avg. of 6 numbers is 8. What will be the 7th number, so that the avg. becomes 10?

Solution:

Let "x" be the 7 th number

Avg. of six numbers = Total of six numbers /6
8 = Total of six numbers /6
8x6 = Total of six numbers
48 = Total of six numbers

Avg. of 7 nos = (Total of six numbers+x) /7
10 = (48+x)/7
10x7 = 48 + x
70 = 48 + x
70-48 = x
22 = x

Therefore x = 22

Hence the seventh number is 22

These are the examples in the topic average

Quote on Mathematics

“Mathematics, without this we can do nothing in our life. Each and everything around us is math.

Math is not only solving problems and finding solutions and it is also doing many things in our day to day life. They are: