Income of Shantanu was ₹ 4000. In the first 2 yr. his income decreased by 10% and 5% respectively but in the third year, the income increased by 15%. What was his income at the end of third year?

Given, P = ₹ 4000
R₁= 10% (decreased), R₂ = 5% (decreases) and R₃ = 15% (growth)
∴ According to the formula,
Income at the end of third year = P(1 - R₁/100)(1 - R₂/100)(1 + R₃/100)
= 4000(1- 10/100) (1 - 5/100) (1 + 15/100)
= 4000 x (9/10) x (19/20) x (23/20)
= 9 x 19 x 23
= ₹ 3933