The student council and the dramatics club of a school share an auditorium for their practice. If both of them started on January 1, and the student council meets once every 3 days while the dramatics club meets once every 5 days, when will they share the auditorium again?
16 January
16 January is correct.
The two groups use the auditorium together again after a number of days that is a common multiple of 3 and 5, and the first such day comes after their LCM.
Since 3 and 5 have no common factor, their LCM is \(3 \times 5 = 15\) days.
Counting 15 days on from 1 January gives \(1 + 15 = 16\), so both meet in the auditorium again on 16 January.
The product of two numbers and their HCF are 4107 and 37 respectively. Find the numbers.
The ratio of the ages of two brothers is 7 : 15. The LCM of their ages is 210. What is the age of the elder brother?
The HCF and LCM of two numbers are 12 and 72, respectively. If the ratio of the two numbers is 2 ∶ 3, then the larger of the two numbers is:
Find the greatest number that will divide 43, 91 and 183 so as to leave the same remainder in each case.
Joseph visits the club on every 5 th day, Harsh visits on every 24 th day, while Sumit visits on every 9 th day. If all three of them met at the club on a Sunday, then on which day will all three of them meet again?
What is the least number which when divided by 12,20 and 24 leaves in each case a remainder of 8?
Which of the following is a pair of co-primes?