If the dairy adds 15 litres of water, what…

If the dairy adds 15 litres of water, what does a litre of the mixture cost it?

Question 25

EasyOriginal question

A dairy buys 60 litres of milk at ₹54 a litre, adds some water, which costs nothing, and sells the mixture at ₹54 a litre.

If the dairy adds 15 litres of water, what does a litre of the mixture cost it?

₹39Correct answerYour answer₹40.50Correct answerYour answer₹43.20Correct answerYour answer₹45Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

The cost is all in the milk: $60 \times 54 = 3{,}240$ rupees, now spread over 75 litres.
$\frac{3{,}240}{75} = 43.20$ rupees a litre.

Worth noting

₹39 takes ₹15 off the price, as if each litre of water lowered the cost by ₹1.

Ten questions from Alligation & Mixtures, at your own pace.

Ten questions from Alligation & Mixtures, at your own pace.