Answer:
Step-by-step explanation:
1. A lighthouse 1 flashes its light every 15 minutes. A lighthouse 2 flashes every 18 minutes. If the two lighthouses flash together at 1:00 A.M, what time they will next flash together?
- Lighthouse 1 every 15 mins. – 15, 30, 45, 60, 75, 90
- Lighthouse 2 every 18 mins. – 18, 36, 54,72,90 LCM is 90 minutes.
90 mins = 1hr and 30mins
So, if the two lighthouses flash together at 1:00 am the next flash will be, 1:00 + 1:30 = 2:30am
2. The length and width of rectangular lot are 108 m and 144 m. Trees are planted at equal distance along the sides of the lot. What is the total number of trees planted?
108 m – 108, 216, 324, 432, 540
144 m – 144, 288, 432 there are 432 Trees that can planted.
3. Leo visits the regional office once every 2 days. Ethan visits once every 4 days while Jaypee visits once every 6 days. They all meet one day in the office. After how many days will they meet together again at the Regional Office?
Leo 2 days - 2, 4, 6, 8, 10, 12,
Ethan 4 days - 4, 8, 12
Jaypee 6 days -6, 12 12 days Leo, Ethan and Jaypee meet together again at the regional Office
4. The box of candies is shared equally among 9,12, or 18 children, there are always 6 candies left. Find the smallest number of candies in the box?
9 - 9, 18, 27, 36, 45, 54, 63
12 - 12, 24, 36, 48, 54
18 - 18, 36, 54 There are 54 candies that shared equally among 9, 12 and
Children. So if there’s 6 candies left, the total of cadies is 60.
5. Three bells toll at intervals of 12 min, 20 min, and 24 min, respectively. If they start by ringing together, after how long will they all ring again?
12mins – 12, 24, 36, 48, 60, 72, 84, 96,108,120
20mins – 20, 40, 60, 80, 100, 120
24mins – 24, 48, 72, 96,120 They will ring at every 120 mins or 2hours.
