Question

If p(q-r)x^2 +q(r-p)x + r(p-q) has equal roots,then, 2/q=??

a)p+ 1/r c)p+r
b) 1/p +r d) 1/p + 1/r

Answer 1

The answer is d) 1/p + 1/r.
Solution to this is,
[r(p-q)/p(q-r)]=1
pr-qr=pq-pr
2pr=pq+qr
2pr/pqr=(pq+qr)/pqr
2/q=1/r+1/p