Question

A stationer buys pens at 5 for Rs 28 and sells them at a profit of $25\%$. How much should a customer pay; if he buys _____________.

• A. Only one Pen?
• B. Three Pens?
• C. Two Pens?
• D. Four Pens?

Answer 1

The correct option is A Only one Pen?

For stationary,

C.P of $5$ pens$=Rs.28$

C.P of $1$ pen$=\frac{28}{5}=Rs.5.60$

Profit$=25\%$

S.P of $1$ pen$=\frac{100+profit\%}{100}\times C.P$ of $1$ pen

$=\frac{100+25}{100}\times Rs5.60$

$=\frac{125}{100}\times Rs5.60$

$=Rs.5\times 1.4=Rs.7$

S.P of $3$ pens$=3\times 7=Rs.21$

Customer pays for

$\left(a\right)$only one pen$=Rs.7$

$\left(b\right)$three pens$=Rs.7\times 3=Rs.21$

$\left(c\right)$two pens$=Rs.7\times 2=Rs.14$

$\left(d\right)$four pens$=Rs.7\times 4=Rs.28$