Question

In a school, the duration of a period in junior sections is 40 minutes and senior section is 1 hour. If the first bell for each section rings at 9: 00 am, when will the two bells ring together again ?

Answer 1

1 hour have 60 minutes which is duration of senior section
40 minutes is the duration of junior section .
60=2×5×6
40 = 2×2×2×5
LCM will be = 2×5×6×2×2 =240
the bell will ring after 240 minutes= 4hrs
9:00 + 4:00 =13:00 = 1:00 pm

Answer 2

Information given :

Given :

First bell rings at 40 min.

Second bell rings at 1 hr

                               = 60 min.

Find the L.C.M

L.C.M of 60 min and 40 min.

60 = 2 × 3 × 10

40 = 2 × 2 × 10

L.C.M = 2 × 10 × 3 × 2

          = 120

L.C.M = 120 min.

          = 2 hr.

Finding the time

Time will hence be :

9 : 00 am + 2 hr

= 11 : 00 am

$\textsf{\underline{\huge{ANSWER}}}$

The bells ring together at 11:00 am

Hope it helps !

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