Question

find the number lying between 700 and 1100 which are divisible by 9 , 12 and 21

Answer 1

any number divisible by 9, 12 & 21 must have tall the factors of each: 
9 = 3*3 
12 = 2*2*3 
21 = 3*7 
LCM = 2*2*3*3*7 = 252 
multiples of 252 greater than 700 and less than 1100: 
756 and 1008 

Answer 2

Answer:

756 and 1008

Step-by-step explanation:

Given : To find the number lying between 700 and 1100 which are divisible by 9 , 12 and 21 .

First find the LCM of the given numbers that is 9, 12 and 21.

The factors we get are 3 x 3 x 4 x 7 = 252. By writing the tables of 252 until we get nearest to 1100 we have

251 x 1 = 251, 251 x 2 = 504, 251 x 3 = 756, 251 x 4 = 1008 and 251 x 5 = 1260.

Now we can consider the two numbers 756 and 1008. They are lying in between 700 and 1100.. These numbers are divisible by all the three numbers 9, 12 and 21.