The document RD Sharma Solutions: Exercise 2.9- Playing With Numbers Class 6 Notes | EduRev is a part of the Class 6 Course Mathematics (Maths) Class 6.

All you need of Class 6 at this link: Class 6

**Q.1. ****Determine the L.C.M of the numbers given below:**

**(i) 48,60**

**(ii) 42,63**

**(iii) 18,17**

**(iv) 15,30,90**

**(v) 56,65,85**

**(vi) 180,384,144**

**(vii) 108,135,162**

**(viii) 28,36,45,60**

**Ans: **

**(i)** Prime factorisation of 48 = 2 × 2 × 2 × 2 × 3

Prime factorisation of 60 = 2 × 2 × 3 × 5

∴ Required LCM = 2 × 2 × 2 × 2 × 3 × 5 = 240

**(ii) **Prime factorisation of 42 = 2 × 3 × 7

Prime factorisation of 63 = 3 × 3 × 7

∴ Required LCM = 2 × 3 × 3 × 7 = 126

**(iii) **Prime factorisation of 18 = 2 × 3 × 3

Prime factorisation of 17 = 17

∴ Required LCM = 2 × 3 × 3 × 17 = 306

**(iv)** Prime factorisation of 15 = 3 × 5

Prime factorisation of 30 = 2 × 3 × 5

Prime factorisation of 90 = 2 × 3 × 3 × 5

∴ Required LCM = 2 × 3 × 3 × 5 = 90

**(v)** Prime factorisation of 56 = 2 × 2 × 2 × 7

Prime factorisation of 65 = 5 × 13

Prime factorisation of 85 = 5 × 17

∴ Required LCM = 2 × 2 × 2 × 5 × 7 × 13 × 17 = 61,880

**(vi) **Prime factorisation of 180 = 2 × 2 × 3 × 3 × 5

Prime factorisation of 384 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3

Prime factorisation of 144 = 2 × 2 × 2 × 2 × 3 × 3

∴ Required LCM = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3 × 5 = 5,760

**(vii)** Prime factorisation of 108 = 2 × 2 × 3 × 3 × 3

Prime factorisation of 135 = 3 × 3 × 3 × 5

Prime factorisation of 162 = 2 × 3 × 3 × 3 × 3

∴ Required LCM = 2 × 2 × 3 × 3 × 3 × 3 × 5 = 1,620

**(viii) **Prime factorisation of 28 = 2 × 2 × 7

Prime factorisation of 36 = 2 × 2 × 3 × 3

Prime factorisation of 45 = 3 × 3 × 5

Prime factorisation of 60 = 2 × 2 × 3 × 5

∴ Required LCM = 2 × 2 × 3 × 3 × 5 × 7 = 1,260

Offer running on EduRev: __Apply code STAYHOME200__ to get INR 200 off on our premium plan EduRev Infinity!

191 videos|224 docs|43 tests