Subject: General Aptitude · Chapter: Alligation or Mixture · Exam: · Marks: · Difficulty:
The cost of Type 1 rice is ` 15 per kg and Type 2 rice is ` 20 per kg. If both Type 1 and Type 2 are mixed in the ratio of 2 : 3, then the price per kg of the mixed variety of rice is
(a)` 18
(b)` 18.50
(c)` 19
(d)` 19.50
Answer
Answer (as printed): A
Explanation
Let the price of the mixed variety be ` x per kg. By the rule of alligation, we have : Cost of 1 kg of Cost of 1 kg of Type 1 rice Type 2 rice ` 15 ` 20 Mean price `x (20 – x) (x – 15) (20 − x ) 2 ∴ = ⇒ 60 − 3 x = 2 x − 30 ( x − 15) 3 ⇒ 5 x = 90 ⇒ x = 18. So, price of the mixture is ` 18 per kg.
Explanation as extracted from the printed page; notation may be imperfect.