Question

Ram ,Sham and Harman started to travel along a circular path.They compleated their round in 15 seconds,16 seconds and 18 seconds respectively.After how much time will they reach their starting point?
1) 303 seconds
2) 720 seconds
3) 704 seconds
4) 364 seconds​

Answer 1

Answer:

• Correct option of this question is 2) 720 seconds.

Step-by-step explanation:

Given that:

• Ram ,Sham and Harman started to travel along a circular path.
• They compleated their round in 15 seconds, 16 seconds and 18 seconds respectively.

To Find:

• After how much time will they reach their starting point?

Concept:

• For finding the time when they reach their starting point we have to find the LCM of the time at which they completed their one round.

Finding the LCM of 15, 16 and 18:

By using Prime factorisation method,

• Prime factors of 15 = 3 × 5
• Prime factors of 16 = 2⁴
• Prime factors of 18 = 2 × 3²

LCM of 15, 16 and 18 = 2⁴ × 3² × 5 = 720

What we get:

• We get 720 as a LCM of 15, 16 and 18. So, we can say that after 720 seconds they reach their starting point.

Answer 2

Given :-

When Ram ,Sham and Harman started to travel along a circular path. They completed their round in 15 seconds,16 seconds and 18 seconds respectively

To find :-

After how much time will they reach their starting point?

Solution :-

Here, the question simply means that we have to find LCM of 15,16,18

On prime factorization

15 = 3 × 5

16 = 2 × 2 × 2 × 2 = 2⁴

18 = 2 × 3 × 3 = 3²

LCM = 720

$\large \sf Option \: B \red \checkmark$