Question

One gear of pulley rotates at a speed of 3 revolutions per second; another gear rotates at 5 revolutions per second. if both start together, after how many seconds will they be together again?

Answer 1

Hey dear,

◆ Answer -

Gears will be together after 15 s .

◆ Explaination-

One gear rotates at 3 rps and other gear at 5 rps.

For both the gears to coincide we have to find LCM (lowest common multiple) of 3 and 5.

Table of 3 => 3,6,9,12,15

Table of 5 => 5,10,15

As LCM is 15, both the gears will conincide after 15 s.

Hope this helps...

Answer 2

Thank you for asking this question.

The options for this question are missing, here are the missing options:

a) 3 sec

b) 5 sec

c) 15 sec

d) 20 sec

The correct answer is Option C: 15

First of all we will take the LCM of 3 and 5.

3. 5

15.

5. 3

(3 rotates 3,6,9,12,15

5 rotates 5,10,15)

If there is any confusion please leave a comment below.