Question

Exercise 3.7
ve the following.
A gardener waters one plant every 7 days and other plants every 3 days. If
he has watered all the plants together today, after how many days will the
gardener water all the plants together again?
Three bells ring at intervals of 10, 12 and 15 minutes. If they rang together at
8:30 a.m., when will they ring together again?
Three cans contain 12 litres, 16 litres and 24 litres of milk. A mug is filled equal
number of times from each can. What is the largest capacity of the mug?​

Answer 1

Answer:

1. After 21 days.

2. At 9:30a.m.

Step-by-step explanation:

1. The next day he will water the plants together = LCM(3,7) = 21

2. 10 = 2×5

12 = 2×2×3 = 2²×3

15 = 3×5

The bells will ring together after = LCM(10,12,15) = highest power of products = 2²×3×5 = 60 mins.

So, they will ring at 9:30a.m.