RRB NTPC Prelims Model Paper 2 with solutions

(4) Given, S.P of 10 notebooks =C.P of 20 notebooks
Let C.P of 1 notebook = ₹1
C.P of 10 notebooks =₹ 10
S.P of 10 notebooks = ₹ 20
Profit = S.P – C.P
=₹ 20 – 10
=₹ 10
Profit% $=\left[\frac{10}{10}\times 100\right]\%$
= 100%