The percentage increase in the amount spent on labour from 1991 to 2001, given that the total amount spent on the construction of the house is 3,60, 000 in 1991 and ‘8,64,000, in 2001 is

Total amount spent in 1991 = 3,60,000

Angle subtended by labour in 1991 = 90°

=> Amount spent on labour in 1991 = $$\frac{90}{360}$$ * 3,60,000 = 90,000

Total amount spent in 2001 = 8,64,000

Angle subtended by labour in 2001 = 100°

=> Amount spent on labour in 2001 = $$\frac{100}{360}$$ * 8,64,000 = 2,40,000

=> % increase in the amount spent on labour from 1991 to 2001 = $$\frac{2,40,000-90,000}{90,000}$$ * 100

= $$\frac{1,50,000}{90,000}$$ * 100 = 166.7%

Ans - (E)