d Word Problems 1 | Job Exam Rare Mathematics (JEMrare) - Solved MCQs

# Word Problems 1

Problem 1: During one year the population of a town increased 5% and during the next it decrease 5%. At the end of the second year the population was 49875. What was the population at the beginning of the first year?

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Solution:

We use here formulas of compound interest for increment and decrement.

for increment the formula is;

and for decrement the formula is ;

1st Year

Data for first year can be arranged as under;

Principal population P = x

Rate of increase R=5%

Term T = 1 Year

Population at the end of 1st Year A=?

As population increase during first year, put these values in formula(1) above;

So Population at the end of 1st year is  whch will  now be the principal population for 2nd year:

2nd Year

Principal population P=

Rate of decrease R = 5%

Term T = 1 year

Population at the end of 2nd year A =?

As population decreases during 2nd year, put these values in formula (2) above;

Thus population at the end of 2nd year is  . But population as given at the end of 2nd year is 49875

So,

So population in the beginning was 50000