Tea worth of  75 Rs./kg &  25 Rs./kg are mixed with a third variety in the ratio 1: 1 : 2. If the mixture is worth Rs. 70 per kg, the price of the third variety per kg will be ?

90

Since first second varieties are mixed in equal proportions, so their average

price = \(\frac{75 + 25}{2}\)=  50 Rs. 

So, Now the mixture is formed by mixing two varieties, one at Rs. 50 per kg

and the other at say Rs. 'x' per kg in the ratio 2 : 2, i.e., 1 : 1.

\(\frac{x -70}{20}\)= 1  => x - 70 = 20  => x = 90 Rs.

 Hence, price of the third variety = Rs. 90 per kg.