The profit percentage on three articles A, B and C is 10%, 20%, and 25% and the ratio of the cost price is 1 : 2 : 4. Also the ratio of number of articles sold of A, B and C is 2 : 5 : 2, then overall profit percentage is:

Answer: Option B

Ratio of CP given as 1 : 2 : 4
Let cost of,
A = x
B = 2x
C = 4x
Ratio of Number of sell is given as 2 : 5 : 2
Let number of items sold be,
A = 2y
B = 5y
C = 2y
Total cost (A + B + C),
= (2xy + 10xy + 8xy)
= 20xy
Profit of A = 0.2xy
Profit of B = 2xy
Profit of C = 2xy
Total profit = 4.2xy
% Profit = $$\frac{4.2\text{xy}\times 100}{20\text{xy}}=21\%$$