What is LCM of two numbers?

In mathematics, least common multiple which is commonly known as LCM is defined as the smallest non-zero number which is divisible by both given numbers 56 and 70.

Properties of LCM

  • The LCM of two given numbers is never less than any of those numbers. Eg- LCM of 56 and 70 is 280, where 56 and 70 are less than 280.
  • LCM is associative which means LCM(56, 70) = LCM(70, 56).
  • LCM is commutative which means LCM(a, b, c) = LCM(LCM(a, b), c) = LCM(a, LCM(b, c)).
  • LCM is distributive, which means LCM(ab, bc, ad) = d * LCM(x, y, z).
  • The LCM of two or more prime numbers is their product.

Steps to find lcm of 56 and 70 by Listing Method

Example: Find lcm of 56 and 70 by Listing Method

  • Multiples of 56: 56, 112, 168, 224, 280, 336, 392, 448, 504, 560, 616, 672, 728, 784, 840, 896, 952, 1008, 1064, 1120, 1176, 1232, 1288, 1344, 1400, 1456, 1512, 1568, 1624, 1680, 1736, 1792, 1848, 1904, 1960, 2016, 2072, 2128, 2184, 2240, 2296, 2352, 2408, 2464, 2520, 2576, 2632, 2688, 2744, 2800, 2856, 2912, 2968, 3024, 3080, 3136, 3192, 3248, 3304, 3360, 3416, 3472, 3528, 3584, 3640, 3696, 3752, 3808, 3864, 3920
  • Multiples of 70: 70, 140, 210, 280, 350, 420, 490, 560, 630, 700, 770, 840, 910, 980, 1050, 1120, 1190, 1260, 1330, 1400, 1470, 1540, 1610, 1680, 1750, 1820, 1890, 1960, 2030, 2100, 2170, 2240, 2310, 2380, 2450, 2520, 2590, 2660, 2730, 2800, 2870, 2940, 3010, 3080, 3150, 3220, 3290, 3360, 3430, 3500, 3570, 3640, 3710, 3780, 3850, 3920

Hence, LCM of 56 and 70 is 280.

Steps to find LCM of 56 and 70 by Common Division Method

Example: Find lcm of 56 and 70 by Common Division Method

2 56 70
2 28 35
2 14 35
5 7 35
7 7 7
1 1

Hence, LCM of 56 and 70 is 2 x 2 x 2 x 5 x 7 = 280.

Steps to find lcm of 56 and 70 by Formula

Example: Find lcm of 56 and 70 by Formula

  • GCF of 56 and 70 = 14
  • LCM of 56 and 70 = (56 x 70) / 14
  • => 3920 / 14

Hence, LCM of 56 and 70 is 280.

Examples

Franky and Joy are running on a circular track. They start at the same time. They take 56 and 70 minutes respectively to go round once. Find at what time they will run together?

Franky and Joy are running on a circular track. They take 56 and 70 minutes respectively to go round once. We need to find out at what time (minimum) they will run together again. For this we need to find the LCM of 56 and 70.
So, LCM of 56 and 70 is 280.

A shopkeeper sells candies in packet of 56 and chocolates in packet of 70. What is the least number of candies and chocolates Annie should buy so that there will be one candy for each chocolate?

The least number of candies and chocolates Annie should buy so that there will be one candy for each chocolate we need to find the lcm of 56 and 70.
So, LCM of 56 and 70 is 280.

Both the cricket team and the rugby team had games, today. The cricket team plays every 56 days and the basketball team plays every 70 days. When will both teams have games on the same day again?

Given that the cricket team plays every 56 days and the basketball team plays every 70 days, so for finding the next time when both teams will play again we need to find the LCM of 56 and 70.
So, LCM of 56 and 70 is 280.

Sammy's company prints 56 textbooks at a time. Daniel's company prints textbooks in sets of 70 at a time. According to a survey done by a committee, both companies printed the same number of textbooks last year. Find the least number of books that each company would have printed.

To find the least number of textbooks that each company could have printed we need to find the LCM of 56 and 70.
So, LCM of 56 and 70 is 280.

Ariel exercises every 56 days and Rubel every 70 days. They both excercised today. How many days will it be until they excercise together again?

The problem can be solved using LCM, because we are trying to figure out the least time until they excercise together again.
So, LCM of 56 and 70 is 280.

What is the relation between LCM and GCF( Greatest Common Factor)?

Greatest common factors or gcf of 56 and 70 is GCF(56, 70) * LCM(56, 70) = (56 x 70) / GCF(56, 70) = 280.

Find the least number which is exactly divisible by 56 and 70.

Least number which is exactly divisible by 56 and 70 is 280.