# Two forces have magnitudes in the ratio of $3:5$ and the angle between their direction is $60^{\circ}$ . If their resultant is $35 N$ their magnitude are

$\begin{array}{1 1}(A)\;12N,20 N \\(B)\;15N,25N \\(C)\;18N,30N\\(D)\;21N,28N \end{array}$

Let the two forces be $3P$ and $5P$ then,
$35^2 =(3P)^2 +(5P)^2+2(3P) (5P) \cos 60^{\circ}$
Hence B is the correct answer.