How to calculate percentage increase

How to calculate the percentage increase of a commodity or goods and service

For example, A clothing shop sells a pair of shoes for #5000 die to inflation the price of the jeans increase by 30%. What is the new price?
Solution
Percentage increase= 30%
Therefore, 30% + 100% = 130%
New Price = 130% times 5000
= 130 x 5000 ÷ (100)
=# 6500

Method 2

Increment = 30% x 5000
= 30 x 5000 ÷ ( 100 )
=# 1500
New price = Old price plus increament
= 1500 + 5000
= # 6500

For example, Tade a civil servant earn #80000. Due to inflation the government increase salary by 20%. What is her new salary ?
Solution
Percentage Increase = 20%
Therefore, 20% + 100%
= 120%
New price = 120% times 80000
= 120 x 80000/( 100)
= 96000

Method 2

Increment = 20% of 80000
= 16000
New price= Old price + increament
= 80000 + 16000
= 96000