In a sequence, each term is obtained by adding 2 to the preceding one. If the sum of the first 20 terms is equal to 140, what is the result of the addition of the first 40 terms?	Answers
A) 1020 B) 1080 C) 1160 D) 1240 E) 1280
a is first term and d = 2 since the preceding number is always greater than the previous one..   Now 20th term is a+19(2).   Sum of n terms is n/2(first term + last term)and here we have to get sum of 20 terms , we get 20/2 ( a + a+38) = 140 ( given sum of 20 terms is 140)   =&gt; 10(2a+38) = 140   =&gt; 2a+38 = 14   =&gt; a = -12   Now to get sum of first 40 terms , we need to get 40th term value i.e. -12+39(2) = 66.   Sum of first 40 terms = 40/2( -12 + 66) = 1080.   Hence option 1080 is correct answer..
<result>B</result>
In a sequence, each term is obtained by adding 2 to the preceding one. If the sum of the first 20 terms is equal to 140, what is the result of the addition of the first 40 terms?