How do we define LCM?

LCM, abbreviation for least common multiple, is defined as the smallest number that is the product of two or more numbers 72 and 99

Properties of LCM

  • The LCM of two given numbers is never less than any of those numbers. Eg- LCM of 72 and 99 is 792, where 72 and 99 are less than 792.
  • LCM is associative which means LCM(72, 99) = LCM(99, 72).
  • 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 72 and 99 by Listing Method

Example: Find lcm of 72 and 99 by Listing Method

  • Multiples of 72: 72, 144, 216, 288, 360, 432, 504, 576, 648, 720, 792, 864, 936, 1008, 1080, 1152, 1224, 1296, 1368, 1440, 1512, 1584, 1656, 1728, 1800, 1872, 1944, 2016, 2088, 2160, 2232, 2304, 2376, 2448, 2520, 2592, 2664, 2736, 2808, 2880, 2952, 3024, 3096, 3168, 3240, 3312, 3384, 3456, 3528, 3600, 3672, 3744, 3816, 3888, 3960, 4032, 4104, 4176, 4248, 4320, 4392, 4464, 4536, 4608, 4680, 4752, 4824, 4896, 4968, 5040, 5112, 5184, 5256, 5328, 5400, 5472, 5544, 5616, 5688, 5760, 5832, 5904, 5976, 6048, 6120, 6192, 6264, 6336, 6408, 6480, 6552, 6624, 6696, 6768, 6840, 6912, 6984, 7056, 7128
  • Multiples of 99: 99, 198, 297, 396, 495, 594, 693, 792, 891, 990, 1089, 1188, 1287, 1386, 1485, 1584, 1683, 1782, 1881, 1980, 2079, 2178, 2277, 2376, 2475, 2574, 2673, 2772, 2871, 2970, 3069, 3168, 3267, 3366, 3465, 3564, 3663, 3762, 3861, 3960, 4059, 4158, 4257, 4356, 4455, 4554, 4653, 4752, 4851, 4950, 5049, 5148, 5247, 5346, 5445, 5544, 5643, 5742, 5841, 5940, 6039, 6138, 6237, 6336, 6435, 6534, 6633, 6732, 6831, 6930, 7029, 7128

Hence, LCM of 72 and 99 is 792.

Steps to find LCM of 72 and 99 by Common Division Method

Example: Find lcm of 72 and 99 by Common Division Method

2 72 99
2 36 99
2 18 99
3 9 99
3 3 33
11 1 11
1 1

Hence, LCM of 72 and 99 is 2 x 2 x 2 x 3 x 3 x 11 = 792.

Steps to find lcm of 72 and 99 by Formula

Example: Find lcm of 72 and 99 by Formula

  • GCF of 72 and 99 = 9
  • LCM of 72 and 99 = (72 x 99) / 9
  • => 7128 / 9

Hence, LCM of 72 and 99 is 792.

Examples

Franky and Joy are running on a circular track. They start at the same time. They take 72 and 99 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 72 and 99 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 72 and 99.
So, LCM of 72 and 99 is 792.

A shopkeeper sells candies in packet of 72 and chocolates in packet of 99. 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 72 and 99.
So, LCM of 72 and 99 is 792.

Both the cricket team and the rugby team had games, today. The cricket team plays every 72 days and the basketball team plays every 99 days. When will both teams have games on the same day again?

Given that the cricket team plays every 72 days and the basketball team plays every 99 days, so for finding the next time when both teams will play again we need to find the LCM of 72 and 99.
So, LCM of 72 and 99 is 792.

Sammy's company prints 72 textbooks at a time. Daniel's company prints textbooks in sets of 99 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 72 and 99.
So, LCM of 72 and 99 is 792.

Ariel exercises every 72 days and Rubel every 99 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 72 and 99 is 792.

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

Greatest common factors or gcf of 72 and 99 is GCF(72, 99) * LCM(72, 99) = (72 x 99) / GCF(72, 99) = 792.

Find the least number which is exactly divisible by 72 and 99.

Least number which is exactly divisible by 72 and 99 is 792.