Each subpart: 3 Marks each
a) Gain in 1 share = Rs (45 - 40) = Rs 5
Gain in 120 shares = Rs 120 × 5 = Rs 600
∴ Gain %=600120×40×100=12.5%
b)
No. of shares bought = Rs 4050 ÷ 90 = 45
S.P. of 1 share = Rs (100 - 30) = Rs 70
S.P. of 45 shares = 70 × 45 = Rs 3,150
C.P. of 45 shares = Rs 4,050
Loss = Rs (4,050 - 3,150) = Rs 900