Slide60.JPG

Slide61.JPG
Slide62.JPG

This video is only available for Teachoo black users

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


Transcript

Ex 5.3, 10 Find the smallest square number that is divisible by each of the numbers 8, 15 and 20.Smallest square number divisible by 8, 15, 20 = L.C.M of 8, 15, 20 Or Multiple of L.C.M Finding L.C.M of 8, 15, 20 L.C.M of 8, 15, 20 = 2 × 2 × 2 × 3 × 5 = 4 × 6 × 5 = 4 × 30 = 120 Checking if 120 is a perfect square We see that, 120 = 2 × 2 × 2 × 3 × 5 Here, 2, 3 & 5 do not occur in pairs ∴ 120 is not a perfect square So, we multiply by 2, 3 and 5 to make pairs So, our number becomes 120 × 2 × 3 × 5 = 2 × 2 × 2 × 3 × 5 × 2 × 3 × 5 3600 = 2 × 2 × 2 × 2 × 3 × 3 × 5 × 5 Now, it becomes a perfect square. So, required number is 3600

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.