Question

The price of an item increased by 3.9 times in the curr ent year as compared to the base year.
What will be the price index number

Answer 1

Answer:

The price of an item is lowered by 15%. By what percent must this discounted price be increased to go back to its original price?

Use the simplest numbers possible and set the original price to 100100. Then, lower the price by 1515%.

100−15100−15 is the 1515% off discounted price

What percentage PP must this discounted price be increased by to go back to its original price? This statement is written as an algebra problem below.

85×p100=10085×p100=100

Solve the problem to get percentage P=100−(p×100)P=100−(p×100).

85×100×p=100×10085×100×p=100×100

8500×p=100008500×p=10000

85008500×p=10000850085008500×p=100008500

1×p=100851×p=10085

p=2017≈1.18p=2017≈1.18

Answer

There is about an 1818% increase.

P=100−(1.18×100)=18P=100−(1.18×100)=18 %