In a test ai students gave wrong answers to at least i questions where i=1,2,..........k.No student gave more than k wrong answers.THen total no. of wrong answers is given is????
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2 Answers
1Total no. of wrong answers given by a1 students = (1+2+...+k).a1 = k(k+1)a1/2
Total no. of wrong answers given by a2 students = (2+3+...+k).a2 = [k(k+1)/2 - 1]a2
and so on...............
adding up all this will give
Total no. of wrong answers given =
k(k+1)/2 x [a1+a2+...+ak] - (n=0Σk-1 (n(n+1).an+1) / 2)
Answer can be expressed in different ways depending on the options provided.
correct me if i am wrong !
