find the spring constant 'k'

Question

A weighing machine consists of a 2 kg pan resting on a spring in this condition, with the pan resting on the spring, the length of the spring is 200 mm. When a mass of 20 kg is placed on the pan, the length of the spring becomes 100 mm. For the spring, the un-deformed length L and the spring constant K (stiffness) are

(a) L = 220 mm, K = 1862 N/m

(b) L = 210 mm, K = 1960 N/m

(c) L = 200 mm, K = 19860 N/m

(d) L = 200 mm, K = 2156 N/m

Answer 1

Given a weighing machine consists of a 2 kg pan resting on a spring in the condition given below