Q. The harmonic mean of roots of cubic equation $2 x^{3} - 5 x^{2} - 7 x + 3 = 0$ is

481 142 Sequences and Series Report Error

A

$\frac{7}{9}$

B

$\frac{9}{7}$

C

$\frac{5}{7}$

D

$\frac{7}{5}$

Solution:

Correct answer is (b) $\frac{9}{7}$