Question

A man sells 12 articles for Rs.80 gaining 33$\frac{1}{3}$ % Find the number of articles bought by the man for 90.

Answer 1

S.P. of 12 articles = rs.. 80,
Gain = $33\frac{1}{3}$%
C.P. = $\frac{100}{(100+Gain)}\times S.P.$
= $\frac{100}{100+\frac{100}{3}}\times 80=\frac{100}{\frac{300+100}{3}}\times 80$
= $\frac{\frac{100}{400}}{3}\times 80=100\times \frac{3}{400}\times 80=Rs.60$
Rs. 60 is the cost of 12 articles
Re.1 is the cost of = $\frac{12}{60}$ article
Rs.90 is the cost of = $\frac{12}{60}\times 90$
= $\frac{1}{5}\times 90$ = 18
Man can buy article for Rs. 90 = 18