Two types of sugar of rate Rs. 5.60/kg and Rs. 6.40/kg is present with a shopkeeper. What quantity of second type of sugar

Two types of sugar of rate Rs. 5.60/kg and Rs. 6.40/kg is present with a shopkeeper. What quantity of second type of sugar should be mixed with 20 kg of first type of sugar to get mixture of rate Rs. 6.20/kg

a)            30 kg

b)            40 kg

c)            50 kg

d)            60 kg

Sol: