Question

How many kilos of tea worth Rs 300 per kg should be mixed with 10 kg of tea worth Rs 240 per kg to produce a mixture to cost Rs 260 per kg

Answer 1

ans = 5kg 
youdo it mix and alligations 
        300            240
                 260
        20              40
(260-240)        300-260
the ratio of 300 and 240 is 1:2 if 240per kg is 10kg so 300kg is 5kg simple

Answer 2

ans is 5kg upper on is right