Register
Two lighthouses flash their lights every 20 seconds and 30 seconds respectively. Given that they flash together at 8 p.m, when will they next flash together?
190k views
5 votes
Two lighthouses flash their lights every 20 seconds and 30 seconds respectively. Given that they flash together at 8 p.m, when will they next flash together?

User Abdul Alim Shakir
by
8.3k points

1 Answer

3 votes
 The first one will flash at every 30 sec and the second one at 20 sec. The second one will go like 1- 4- 8 and then to 12. By the time the second one will reach first at 6 and then on 12. So, after every 1 minute they will flash together. 
User Farkhod Abdukodirov
by
8.8k points
← Prev Question Next Question →

Related questions

Ask a Question
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Other Questions

What is .725 as a fraction
How do you estimate of 4 5/8 X 1/3
A bathtub is being filled with water. After 3 minutes 4/5 of the tub is full. Assuming the rate is constant, how much longer will it take to fill the tub?
i have a field 60m long and 110 wide going to be paved i ordered 660000000cm cubed of cement  how thick must the cement be to cover field
Write words to match the expression. 24- ( 6+3)
Link Copied!