Answer: 14.29%
Step-by-step explanation:
Let C be the cost of 1 article and S the selling price for 1 article. The profit, P, for 1 article would be:
P = S - C
For n articles, the total profit would be
nP = nS - nC
Profit percentage would be (P/S)*100%
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We know that 21C = 18S: This can be written as C = (18/21)S
P = S - C
P = S - (18/21)S
P = (3/21)S or P=(1/7)S
Profit percentage would therefore be
(P/S)*100%
((1/7)S/S)*100%
(1/7)*100%
= 14.29%
