HCF and LCM word problems

Three bells toll together at the same time after the first bell stays quiet for 12 seconds, the second bell for 15 seconds and the third bell for 18 seconds. During a duration of 30 minutes, how many times will the three bells toll together?

• 10

• 11

• 12

• 15

Two neon signs are turned on at the same time. Both signs blink as they are turned on. One sign blinks every 9 seconds. The other sign blinks every 15 seconds. In how many seconds will they blink together again?

• 45 seconds

• 8 seconds

• 16 seconds

• 48 seconds

Melanie and Martin are both building a toy train track out of connecting pieces. Melanie has pieces that are 8 inches long while Martin's pieces are 20 inches long. How long will the shortest track be that they can each build with the same length?

• 20

• 4

• 40

• 2

Mrs. Evans has 120 crayons and 30 pieces of paper to give to her students. What is the largest number of students she can have in her class so that each student gets equal number of crayons and equal number of paper.

• None of the above

• LCM

• Not enough information

• HCF

Samantha has two pieces of cloth. One piece is 72 inches wide and the other piece is 90 inches wide. She wants to cut both pieces into strips of equal width that are as wide as possible. How wide should she cut the strips?

• LCM

• HCF

• Not enough information

• None of the above

Two bikers are riding a circular path. The first rider completes a round in 12 minutes. The second rider completes a round in 18 minutes. If they both started at the same place and time and go in the same direction, after how many minutes will they meet again at the starting point?

• Not enough information

• HCF

• None of the above

• LCM

The number of students in three sections A, B, and C of class VI in The Millennium school are 30, 35 and 40. Find the minimum number of books required for the class library for equal distribution in section A, B and C.

• LCM

• None of the above

• HCF

• Not enough information

Rosa is making a game board that is 16 inches by 24 inches. She wants to use square tiles. What is the largest tile she can use?

• HCF

• Not enough information

• LCM

• None of the above

Two friends, Alice and Bob, are running around a circular track. Alice completes a lap in 20 seconds, while Bob completes a lap in 25 seconds. If they start at the same point and time, after how many seconds will they meet again at the starting point?

• 100 seconds

• 125 seconds

• 50 seconds

• 75 seconds

Alice has a piece of ribbon that is 36 inches long, and Bob has a piece that is 48 inches long. They want to cut the ribbons into equal lengths. What is the maximum length they can cut the ribbons into?

• 12 inches

• 24 inches

• 6 inches

• 18 inches