In what ratio must a grocer mix two varieties of pulses costing Rs. 15 and Rs. 20 per kg respectively so as to get a mixture worth Rs. 16.50 kg?	Choose the correct answer:
A) 3 : 7
B) 5 : 7
C) 7 : 3
D) 7 : 5
E) 6 : 5
By the rule of alligation:   Cost of 1 kg pulses of 1st kind Rs. 15   Cost of 1 kg pulses of 2nd kind Rs. 20   Mean Price Rs. 16.50   Required rate = 3.50 : 1.50 = 7 : 3.   Answer:7 : 3
<result>C</result>
In what ratio must a grocer mix two varieties of pulses costing Rs. 15 and Rs. 20 per kg respectively so as to get a mixture worth Rs. 16.50 kg?