Traffic light at one particular crossing change after every 40 seconds. The traffic light at the next crossing changes after every 32 seconds. At a certain time they change together. After what time they will change together?
- A. 2 min. 40 sec.
- B. 1 min. 20 sec.
- C. 3 min. 20 sec.
- D. 2 min. 20 sec.
Answer: A. 2 min. 40 sec.
Explanation: LCM of 40 seconds and 32 seconds = 160 seconds = 2 minutes and 40 seconds.