Efficiency = \( \frac{W(120N)INPUT}{WORK OUTPUT} \times \frac{100}{1} \)
And for incline plane
V.R =\( \frac{1}{Sin\theta} \\
= V.R = \frac{1}{Sin30} =\frac{1}{0.5} = 2 \\
\text{therefore } \frac{60}{120} = \frac{M.A}{2}
=M.A = \frac{120}{100} = 1.2\\
\text{but M.A } = \frac{load}{effort} = \frac{120}{E}\\
\text{therefore} \frac{120}{E} = 1.2 \\
= E =\frac{120}{1.2 } = 100N \\ \)
Therefore Effort up the plane = 100N