Ex 2.2, 15 - I have a total of 300 in coins of denomination 1, 2 and 5

Ex 2.2, 15 - Chapter 2 Class 8 Linear Equations in One Variable - Part 2
Ex 2.2, 15 - Chapter 2 Class 8 Linear Equations in One Variable - Part 3

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class


Transcript

Question 15 I have a total of Rs 300 in coins of denomination Re 1, Rs 2 and Rs 5. The number of Rs 2 coins is 3 times the number of Rs 5 coins. The total number of coins is 160. How many coins of each denomination are with me?Let Number of Rs 5 coin = x Given number of Rs 2 coins is 3 times number of Rs 5 coins ∴ Number of Rs 2 coins = 3x Also, given that Total number of coins = 160 No. of Rs 5 coins + No. of Rs 2 coins + No. of Rs 1 coin = 160 x + 3x + Number of Rs 1 coin = 160 4x + Number of Rs 1 coin = 160 Number of Rs 1 coin = 160 − 4x Given, Total amount = Rs 300 160 − 4x + 6x + 5x = 300 160 − 4x + 11x = 300 160 + 7x = 300 7x = 300 − 160 7x = 140 Rough If I have one 5 Rs coin, then Amount = 1 × 5 = 5 If I have 2 Rs 5 coins, then Amount = 2 × 5 = 10 If I have 3 Rs 5 coins, then Amount = 3 × 5 = 15 x = 140/7 x = 20 Therefore, Number of 5 Rs coins = x = 20 Number of 2 Rs coins = 3x = 3 × 20 = 60 Number of Re 1 coins = 160 − 4x = 160 − 4 × 20 = 160 − 80 = 80

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.