(c) ₹ 32.5 The salesman gets the bonus on selling of articles worth ₹ x = ₹ (
x
100
−1) For January, he gets bonus of (
100
100
−1) = ₹ 0 For February, bonus = (
200
100
−1) = ₹ 2 For March to November bonus = 9 (
300
100
−1) = 9 x 2 = ₹ 18 For December, bonus = (
1200
100
−1) = ₹ 11 Total bonus = ₹ (1 + 18 + 11) = ₹ 30 Total salary of the year = ₹ (12 x 30) = ₹ 360 ∴ Average income per month during the year = ₹