Ex 8.2, 1 - A man got a 10% increase in his salary. If his new salary

Ex 8.2, 1 - Chapter 8 Class 8 Comparing Quantities - Part 2
Ex 8.2, 1 - Chapter 8 Class 8 Comparing Quantities - Part 3

Ex 8.2, 1 - Chapter 8 Class 8 Comparing Quantities - Part 4

Ex 8.2, 1 - Chapter 8 Class 8 Comparing Quantities - Part 5

 

 


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 − x = Increase in salary Increase in salary = 154000 − x Now, Percentage increase = (𝐼𝑛𝑐𝑟𝑒𝑎𝑠𝑒 𝑖𝑛 𝑠𝑎𝑙𝑎𝑟𝑦)/(𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝑠𝑎𝑙𝑎𝑟𝑦) × 100 10 = (154000 − 𝑥)/𝑥 × 100 10x = (154000 − 𝑥) × 100 10𝑥/100 = 154000 − 𝑥 𝑥/10 = 154000 𝑥/10 + 𝑥 = 154000 𝑥 (1/10+1) = 154000 𝑥 ((1 + 10)/10) = 154000 𝑥(11/10) = 154000 𝑥 = (154000 × 10)/11 ∴ 𝑥 = 140000 ∴ 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 = 𝑥 + increase in salary 154000 − 𝑥 = increase in salary ∴ Increase in salary = 154000 − 𝑥 Now, Increase in salary = Percentage increase × Old Salary 154000 − 𝑥 = 10% × 𝑥 154000 − 𝑥 = 10/100 × 𝑥 154000 − 𝑥 = 1/10 𝑥 154000 = 1/10 𝑥 + 𝑥 154000 = 𝑥 (1/10+1) 154000 = 𝑥 ((1 + 10)/10) 154000 = 𝑥 (11/10) 154000/11 × 10 = 𝑥 1540000/11 = 𝑥 140000 = 𝑥 ∴ 𝑥 = 140000 ∴ Original salary is Rs 1,40,000

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.