Question

INa school the duration of a class in primary section is 40min and in the secondary section is 50 min .if both the section being at 8am when will bells of two sections ring together again​

Answer 1

First bell rings at 8:00 am

The duration of a class in primary section is 40 min

The duration of a class in primary section is 50 min

LCM of 40 and 50

$40 = {2}^{3} \times 5 {}^{1}$

$50 = {2}^{1} \times {5}^{2}$

$\bold{LCM = 8 \times 25 = 200}$

$\bold{\cancel\dfrac{200}{50} = 4 \: hour}$

$= 8 + 4= 12$

So, the bells of two sections ring together again in 12 am.