‘Averages and Percentages’ is a very easy and interesting topic in Quantitative aptitude for SSC exams. Generally, 1-2 questions can be seen from this topic in the exam. For finding averages among any set of numbers, first, we need to add them with each other and then the quantity of numbers will be divided. Percentages can be calculated on one number with respect to the other number.
Average = $$\frac{\text{Sum of data}}{\text{Number of data}}$$
Percentage (%) = $$\frac{X}{Y}\times100$$
Here X = Actual number.
Y = Total number.
If X is greater than Y, then the percentage increase = $$\frac{(X-Y)}{Y}\times100$$.
If X is smaller than Y, then the percentage decrease = $$\frac{(Y-X)}{Y}\times100$$.
Q) Find out the average of the numbers 20, 35, 38 and 25.
Sol. Average = $$\frac{20+35+38+25}{4}$$
= $$\frac{118}{4}$$
= 29.5
Q) 120 is what percent of 50?
Sol. Percentage = $$\frac{120}{50}\times100$$
= 240%
