John sells cornflour at the rate of Rs. 5.10 per kg and gains a profit of 20%. If he decreases the price so as to gain only 25 p. per kg, what should be the ratio in which the sales should increase so as to get the same amount of profit?

A. 1:03

B.5:17

C.17:05

D.12:17

B.5:17

Cp is 51* 5/6 = 4.25 per kg so earlier the profit was 0.85 per kg

now the profit if 0.25 per kg

so 0.25 :0.85 = 5:17