The population of a particular area of a city is 5000. It increases by 10% in 1styear. It decreases by 20% in the 2nd year because of some reason. In the 3rd year, the population increases by 30%. What will be the population of area at the end of 3 years?

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

5120

5300

5720

5620

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

It is given,
Population of a city at the starting of first year =5000.
It increases by 10% in 1st year,
Population at the end of 1st year = Population at the starting of 2nd year,

5000 + 10 % of 5000

\Rightarrow 5000 + \frac{10}{100} \times 5000

\Rightarrow = 5500

It decreases by 20% in 2nd year.
Population at the end of 2nd year = Population at the starting of 3rd year,

5500 - 20 % of 5500

\Rightarrow 5500 - \frac{20}{100} \times 5500

\Rightarrow 5500 - 1100

\Rightarrow 4400

It increases by 30% in 3rd year,
Population at the end of 3rd year

= 4400 + 30 % of 4400

\Rightarrow 4400 + \frac{30}{100} \times 4400

\Rightarrow 4400 + 1320

\Rightarrow 5720

Therefore, the population of area at the end of 3 years is

5720

.
Hence, the correct option is (3) .

Watch 3-min video & get full concept clarity

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET

How to Join IIT after 10th

🔥 Start Your JEE/NEET Prep at Just ₹1999 / month - Limited Offer! Check Now!

Get Expert Academic Guidance – Connect with a Counselor Today!

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET

How to Join IIT after 10th