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)/2 ?
Choose the correct choice from the following answers
A) 1	B) 10	C) 19	D) 5	E) 2
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)/2= 110 - 100= 
<gadget id="calculator">110 - 100</gadget>
<output>10</output>
10/2= 
<gadget id="calculator">10/2</gadget>
<output>5</output>
5   Ans :5
<result>D</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)/2 ?