Grade 5 Math Questions and Problems With Answers on Lowest Common Multiple
Grade 5 math questions and problems on Lowest Common Multiple (LCM
) with answers are presented.
In the questions below, Lowest Common Multiple is written as LCM.

Find the first 4 multiples of each number.
 2
 3
 5
 7
 10

Find the LCM of each pair of numbers.
 2 , 5
 4 , 5
 7 , 5
 12 , 6

Find the LCM of each triplet of numbers.
 2 , 3 , 12
 4 , 5 , 20
 5 , 6 , 10
 3 , 6 , 7

Find two numbers smaller than 10 and have an LCM equal to 20.

Find two numbers that have an LCM equal to 6 and their sum is equal 9.

3 balls rotate along a circular track. Ball A makes one full rotation in 6 seconds. Ball B makes 9 seconds and ball C makes 12 seconds. If the three balls start rotating from the same point and at the same time now, after how many seconds will they all be at the same point again?

3 bulbs are used to make a flashing game. Bulb A flashes every 5 seconds. Bulb B flashes every 10 seconds and bulb C flashes every 25 seconds. If the game is switched on now, in how many seconds will all three bulbs flash at the same time?


Answers to the Above Questions

 2 : 2,4,6,8
 3 : 3,6,9,12
 5 : 5,10,15,20
 7 : 7,14,21,28
 10 : 10,20,30,40

 2 , 5 : 10
 4 , 5 : 20
 7 , 5 : 35
 12 , 6 : 12

 2 , 3 , 12 : 12
 4 , 5 , 20 : 20
 5 , 6 , 10 : 30
 3 , 6 , 7 : 42
 (4,5)
 (3,6)
 36 seconds
 50 seconds
More Primary Math (grades 4 and 5) with Free Questions and Problems With Answers
More Middle School Math (grades 6,7,8 and 9) with Free Questions and Problems With Answers
More High School Math (Grades 10, 11 and 12)  Free Questions and Problems With Answers
Author 
email
Home Page
Updated: 14 March 2009 (A Dendane)