In a sequence, each term is obtained by adding 7 to the preceding one. If the sum of the first 30 terms is equal to 705, what is the result of the addition of the first 40 terms? Pick one.
A) 2000
B) 2250
C) 2340
D) 2400
E) 2440
a is first term and d = 7 since the preceding number is always greater than the previous one..   Now 30th term is a+29(7).   Sum of n terms is n/2(first term + last term)and here we have to get sum of 30 terms , we get 30/2 ( a + a+203) = 705 ( given sum of 30 terms is 705)   =&gt; 15(2a+203) = 705   =&gt; 2a+203 = 47   =&gt; 2a=-156   =&gt; a = -78   Now to get sum of first 40 terms , we need to get 40th term value i.e. -78+39(7) = 195.   Sum of first 40 terms = 40/2( -78 + 195) =2340 .   Hence option 2340 is correct answer..
<result>C</result>
In a sequence, each term is obtained by adding 7 to the preceding one. If the sum of the first 30 terms is equal to 705, what is the result of the addition of the first 40 terms?