Find the least perfect square, which is divisible by 5,12,18 and 21
Answers
Answered by
1
Step-by-step explanation:
Find the LCM of given numbers. Square it to get the answer.
8 = 2^3
12 = 2^2 * 3
15 = 3 * 5
20 = 2^2 * 5
LCM = 2^3 * 3 * 5
= 120
Answer = LCM^2
= 14400
It is not given in the options.
Edit :
I made a mistake. Thank you for pointing it out .
The correct method would be
Find the LCM of the given numbers(which is 120 in this case)
Find the prime factorisation of the LCM
(120 = 2^3 *3 *5)
Now multiply the LCM by prime factors so that all the prime factors will have even multiplicities.
Answer = (2^3 * 3* 5) * (2*3*5)
= 2^4 * 3^2 * 5^2
= 3600
Similar questions