37 vote
A shopkeeper mixed three qualities of wheat flour costing Rs. 20 per kg, Rs. 25 per kg and Rs. 28 per kg in the ratio 3 ∶ 4 ∶ 5 respectively. At what price should he sell a 10 kg bag of the flour mixture to earn a profit of 30%?
A shopkeeper mixed three qualities of wheat flour costing Rs. 20 per kg, Rs. 25 per kg and Rs. 28 per kg in the ratio 3 ∶ 4 ∶ 5 respectively. At what price should he sell a 10 kg bag of the flour mixture to earn a profit of 30%?
1). Rs. 325
2). Rs. 360
3). Rs. 375
4). Rs. 390
1 answers
31 vote
Let the shopkeeper mixed 3a kg of flour costing Rs. 20 per kg, 4a kg of flour costing Rs. 25 per kg and 5a kg of flour costing Rs. 28 per kg
⇒ Total quantity of mixture = 3a + 4a + 5a = 12a kg
⇒ Cost price of 12a kg mixture = (3a × 20) + (4a × 25) + (5a × 28) = 60a + 100a + 140a = Rs. 300a
⇒ Cost price of 10 kg mixture = 300a × (10/12a) = Rs. 250
Now, in order to earn a profit of 30%,
⇒ Selling price of 10 kg mixture = 250 + 30% of 250 = 250 + 75 = Rs. 325