Ex 7.2

Chapter 7 Class 8 Comparing Quantities
Serial order wise

### Transcript

Question 1 (Method 1) A man got a 10% increase in his salary. If his new salary is Rs 1,54,000, find his original salary. Given, Increase Percentage = 10% New salary = 154000 Let the original salary be x Now, New salary = Original salary + Increase in salary 154000 = x + Increase in salary 154000 β x = Increase in salary Increase in salary = 154000 β x Now, Percentage increase = (πΌππππππ π ππ π πππππ¦)/(ππππππππ π πππππ¦) Γ 100 10 = (154000 β π₯)/π₯ Γ 100 10x = (154000 β π₯) Γ 100 10π₯/100 = 154000 β π₯ π₯/10 = 154000 π₯/10 + π₯ = 154000 π₯ (1/10+1) = 154000 π₯ ((1 + 10)/10) = 154000 π₯(11/10) = 154000 π₯ = (154000 Γ 10)/11 β΄ π₯ = 140000 β΄ Original salary is Rs 1,40,000 Question 1 (Method 2) A man got a 10% increase in his salary. If his new salary is Rs 1,54,000, find his original salary.Let the original Salary be x Now, New salary = Original salary + increase in salary 154000 = π₯ + increase in salary 154000 β π₯ = increase in salary β΄ Increase in salary = 154000 β π₯ Now, Increase in salary = Percentage increase Γ Old Salary 154000 β π₯ = 10% Γ π₯ 154000 β π₯ = 10/100 Γ π₯ 154000 β π₯ = 1/10 π₯ 154000 = 1/10 π₯ + π₯ 154000 = π₯ (1/10+1) 154000 = π₯ ((1 + 10)/10) 154000 = π₯ (11/10) 154000/11 Γ 10 = π₯ 1540000/11 = π₯ 140000 = π₯ β΄ π₯ = 140000 β΄ Original salary is Rs 1,40,000