Question

pleeeeease tell me what is the use of HCF and LCM i got a project about it tomorow

Answer 1

Factorize the LCM 20 = 2 x 2 x 5 Factorize the HCF 300 = 2 x 2x3x5x5 The HCF is the common factor for both numbers whereas the LCM contains all the unique factors of both numbers. So, 2 x 2x5 or 20 is a common factor for both numbers. The factors remaining are 3 and 5.

Answer 2

The use of HCF-
1. Suppose you are a teacher in a school and you have to arrange students in minimum rows. 21 students from sixth class ,42 students from seventh and 56 students from eigth class in such a way that students in a row belongs to same class. You just take hcf of numbers and that is 7. So, 3 rows ,6 rows and 8 rows of students can arranged. Total 17rows .Now you have an idea of space for this arrangement and it will look pretty well.
2. You work in a pipe factory and you have so many extra bundles of pipes of different length .You have to cut the minimum no of pipes with low wastages and put them together. What will you do?
You took the hcf of all lengths and cut the pipes of the hcf value length. FOR example- you have extra pipes with 24m,48m,72m,36m lengths.Take hcf and we get 12. SO,12m length is the maximum length ,we can cut with minimum wastages. And let there are only four bars or pipes the number of 12m length pipe is (2+4+6+3)=(15)pipes we have.
We can apply this in textile works for saving our clothes.

The use of LCM

In daily life suppose you are in a traffic controller job . You have to set the timmings of traffic lights in such a way that all are not green at the same time or specially not in the rush hour. It may creats problem in an hour because lights are for few minutes only. Take the timmings of nearby places in same area and calculate lcm of your times of all traffic stops.Then you can easily manage the traffic by increase the durations or set at different (-/+ few minutes) times.