Question

Find the sum of all the odd numbers between 27 and 361 inclusive.

Answer 1

Answer:

32592

Step-by-step explanation:

In this question we know the first term and the last term,and we also know that all the numbers to be taken sum off are odd;

hence we can conclude that

• a(i.e. first term)=27
• d(common difference)=2
• n th term is 361

Thus we will apply formula

nth term= a+(n-1)d ; [here n is the total no. of terms in a series]

Or 361=27+(n-1)2

Or 361-27+2=2n

Or 336=2n

therefore n=168

so now we have

• a=27,
• d=2,
• L or nth term= 361

Thus we can apply the formula of summesion of an AP( arithematic progressionn)= {n(a+L)}/2

Or {168(27+361)}/2

Or {168(388)}/2

Or {65184}/2

= 32592