The sum of the squares of three numbers is 138,while the sum of their products take two at a time is 131.Find the sum?	Choose the correct choice from the following answers.
A) 10
B) 30
C) 20
D) 50
E) 40
Formula is (a+b+c)^2=(a^2)+(b^2)+(c^2)+2(ab+bc+ca)   =138+(2*131)   The sum of the three numbers a+b+c=√400=20   Answer is option 20
<result>C</result>
The sum of the squares of three numbers is 138,while the sum of their products take two at a time is 131.Find the sum?