Ifaequals the sum of the even integers from 2 to 20, inclusive, andbequals the sum of the odd integers from 1 to 19, inclusive, what is the value of a + b ? Options.
A) 110 B) 100 C) 190 D) 200 E) 210
Answer is 10   Yes! there is really a faster way to solve it.   Sum of consecutive odd or even integers = (no. of odd or even ints) * (first int + last int) / 2   Here A = sum of even ints from 2 to 20, inclusive   number of even ints = 10,   first int + last int = 2+20= 
<gadget id="calculator">2+20</gadget>
<output>22</output>
22   A= 10*22 / 2= 
<gadget id="calculator">10*22 / 2</gadget>
<output>110</output>
110   B= sum of odd ints from 1 to 19, inclusive   number of odd ints = 10,   first int + last int = 1+19= 
<gadget id="calculator">1+19</gadget>
<output>20</output>
20   A= 10*20 / 2= 
<gadget id="calculator">10*20 / 2</gadget>
<output>100</output>
100   A+B= 110 + 100= 
<gadget id="calculator">110 + 100</gadget>
<output>210</output>
210   Ans :210
<result>E</result>
Ifaequals the sum of the even integers from 2 to 20, inclusive, andbequals the sum of the odd integers from 1 to 19, inclusive, what is the value of a + b ?