By selling 30 oranges for a rupee a man losses 30%. How many oranges should he sell for Rs.1 to earn 40% profit?

14 15 18 20

15

CP = \(\frac{1}{30}\) × \(\frac{100}{70}\) = \(\frac{1}{21}\) SP = \(\frac{1}{21}\) × \(\frac{140}{100}\) = \(\frac{1}{15}\) Therefore, he should sell 15 oranges for Rs. 1.