The mean daily profit made by a shopkeeper in a month of 30 days was Rs. 350. If the mean profit for the first twenty days was Rs 400, then the mean profit for the last 10 days would be
(a) Rs 200
(b) Rs 250
(c) Rs 800
(d) Rs 300
Correct option (b)
Explanation:
30 × 350 = 20 × 400 + 10 × x
⇒ 10x = 10500 – 8000
⇒ 10x = 2500
⇒ x = 250
