Three red lights on the same road start blinking at the same time and blink repeatedly after every 4, 6, and 8 minutes, respectively. How many times will they blink together in an interval of 3 hours, excluding blinking together at the starting moment?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 7.
LCM of 4, 6, and 8 = 24 minutes
Total time = 3 hours = 180 minutes
Number of times they blink together (excluding start) = = 7.5 = 7 times