The selling price of 7 articles is the same as the cost price of 4 articles. The gain or loss percent is:

40\(\frac{6}{7}\)% 45\(\frac{6}{7}\)% 42\(\frac{6}{7}\)% 34\(\frac{6}{7}\)%

42\(\frac{6}{7}\)%

ATQ, ⇒ S.P. of 7 =  C.P. of 4 ⇒ C.P. : S.P. = 7 : 4 ⇒ Loss = 7 - 4 = 3 ⇒ Loss percentage = \(\frac{3}{7}\) × 100 =  42\(\frac{6}{7}\)%