Maths Olympiad Exam Numerical Ability

if x1,x2,x3...................xn are in AP then 1/x1x2+1/x2x3+................+1/x(n-1)xn is equal to
a)(n+1)/x1
b)(n-1)/x2
c)(n-1)/x1xn
d)(n+1)x1x2

Read Solution (Total 2)

option c is correct
9 years agoHelpfull: Yes(2) No(0)

ans is c
1/x1x2+1/x2x3.....1/x(n-1)xn=(n-1)/x1xn
9 years agoHelpfull: Yes(1) No(0)

Maths Olympiad Other Question

for what value of m the equation 2mx^2-2(1+2m)x+(3+2m)=0 have equal roots if sum of terms of AP 25,22,19,....... is 116 then the lat term is