Solution -
The ratio of CP of A, B and C = 1 : 2 : 4
Let,
CP of A = 1x
CP of B = 2x
CP of c = 4x
The ratio of number of articles sold of A, B and C is 2 : 5 :2.
Number of article sold by A = 2y
Number of article sold by B = 5y
Number of article sold by C = 2y
So,
The total cost price of A, B and C = 2xy + 10xy + 8xy
= 20xy
The profit percentage on three articles A, B and C is 10%, 20% and 25%
Profit of A = 2xy (10/100)
= 0.2xy
Profit of B = 10xy (20/100)
= 2xy
Profit of C = 8xy (25/100)
= 2xy
Total profit of A, B and C = 0.2xy + 2xy + 2xy
= 4.2xy
SO,
Profit percentage = (Total profit / Total CP) × 100
= (4.2xy / 20xy) × 100
= 21%
Hence, The correct answer is option (b) 21%.
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