Question

(10. The smallest number which is divisible by
12, 15, 20 and is a perfect square
(a) 400 (b) 1000 (0) 900 (d) 1600​

Answer 1

Step-by-step explanation:

1. 12=2x2x3
2. 15=3x5
3. 20=2x2x5
4. LCM =2x2x3x5=60

here 3and 5 are not in pair

so we need to multiply 60by 3and 5

number=900

Answer 2

Prime Factorisation of these numbers

12= 2×2×3

15=3×5

20= 2×2×5

LCM of 12,15 and 20 =2×2×3×5 = 60

As 3 and 5 are not in pair in LCM's factor so we need to multiply 60 by 5 and 3 to make it a perfect square

So , Required number = 60 ×3×5=900

Therefore, option (c) 900 is correct