d Word Problem 17 (Population of a town) | Job Exam Rare Mathematics (JEMrare) - Solved MCQs

# Word Problem 17 (Population of a town)

Problem 17 : During the first year the population of a town increases by 4% and during second year it diminished by 4%. If at the end of the second year its population was 2496 then initially the population was;

a. 2400          b. 2550             c. 25000         d. 2500

basic arithmetic test for jobs, workplace math tests –

basic mathematics mcqs with solution

Solution :

Its a problem of compound interest ! On population we apply compound interest calculator or compound interest formula here  – lets start!

Increase Case

Here,

Let us suppose;

y= population at the start of first year=?

R= rate of increase =4%

A=Population at the end of first year=?

T= Time duration in year=1

Since this is case of increase – we use +ve formula   Decrease Case

Population diminish in the second year. Here, (Since population at the end of the first year is now initial population for the second year ! )

R= Rate of decrease =4%

T= Time in years= 1

A=2496 (population at the end of second year)

Since this is case of decrease – we use -ve formula; Putting values of variables for second year;  But A=2496   So, the population at the beginning of first year was 2500 Copyright secured by Digiprove © 2020