The sum of 3 consecutive odd numbers is 69 .What is the third number in this sequence ?

Solution:

We need to find out the  third odd number  from  consecutive odd number sequence.

 

                      Step-1:

We have to have knowledge about odd number . If you divide a odd number by 2 ,you will get a remainder.,i.e. an odd number is not exactly divisible by 2.

Now you have to understand about consecutive odd number.The difference between two consecutive odf number  is always 2.

 

 

                Step-2:

Say,the first odd number is x.

So, the second odd number will be x+ 2. Thus, the third consecutive odd number will be x+4 .

Have a look here.

The three consecutive odd numbers are x, x+2,x+4 ,respectively.

                  Step-3:

According to the conditions,the sum of 3 consecutive odd numbers will be 69.

 

So, we are getting the following equation

 

x +( x+2)+(x+4)  = 69

Or, 3x + 6 = 69

Or,3x + 6 – 6 = 69 - 6 [ Deduct 6 from both sides ]

Or, 3x + 0 =  63

Or, 3x = 63

Or, 3x/3 =  63/3

[Divide both sides by 3]

Or, x = 21

Now put the value of x here:

x, x+2,x+4 

= 21, 21+2 , 21+4

=21,    23,    25  

So, the third number of this sequence is 25 .

Answer:25