Question

13. In a school, the bell for the primary section goes every 30 minutes and the bell for the middle school section goes every 45 minutes. If the school starts at 8:00 a.m., at what time will both the primary and the middle school sections start next periods together?हाय ​

Answer 1

Step-by-step explanation:

Time at which bell for all these section will ring together will be equal to the LCM of 30,40 and 45

2 | 30, 40, 45

5 | 15, 20, 45

3 | 3 , 4 , 9

3 | 1 , 4 , 3

2 | 1 , 4 , 1

2 | 1 , 2 , 1

1 , 1 , 1

LCM = 2 × 2 × 2 × 3 × 3 × 5

= 8 × 9 × 5

= 72 × 5

= 360

Hence all three bell will ring together after 360 min

= 6 hr

that is 3 PM

HOPE THIS HELPED

PLS MARK AS BRAINLIEST

Answer 2

Explanation:

$\mathsf{30=2\times \mathbf{3\times5}}$

$\mathsf{45=3\times \mathbf{3\times5}}$

∴ LCM of 30 and 45 is 2 x 3 x 3 x 5 = 90.

Hence, both sections will have their next periods together after 90 minutes, that is, 1 hour and 30 minutes.

8:00 + 1:30 = 9:30

Hence, both section will start a new period together at 9:30.

Answer: 9:30 am.

I hope this helps. :D