Question

Section B
Q.1:(A) The traffic lights at three different
road crossings change after every 48
seconds, 72 seconds and 108 seconds
respectively. If they change simultaneously
at 7 a.m., at what time will they change
simultaneously again? (4 marks)
1. Add File
Q.1(B): Write the smallest digit in the blank
space of the following number so that the
number formed is divisible by 3:4765 2.
(2 Marks)
1. Add File​

Answer 1

Answer:

I didn't know the answer of this question because now I am in class 7th

Answer 2

Answer:

1. 7 min 12 sec

Step-by-step explanation:

ans 1. Given that traffic light at three different road crossing change after every 48 seconds,72 seconds and 108 seconds respectively.

48 = 2 × 2 × 2 × 2 × 3

72 = 2 × 2 × 2 × 3 × 3

108 = 2 × 2 × 3 × 3 × 3

Taking LCM for,

48, 72 and 108 i.e (2 × 2 × 2 × 2 × 3 × 3 × 3)= 432

We have,

432 seconds = 7 min 12 seconds

Hence,after 7 min and 12 seconds they will blink simultaneously.