Question

The selling price of 12 pens is equal to the cost price of 10 pens.What is the profit per cent?

Answer 1

Answer : Loss% = 16.67%

Solution :
_________

Given that : Selling Price of 12 pens is equal to the cost price of 10 pens.

Now, according to the question :

$S.P. \: of \: 12 \: pens \: = C.P. \: of \: 10 \: pens \: \\ \\ = > S.P. \times 12 = C.P. \times 10 \\ \\ = > \frac{S.P.}{C.P.} = \frac{10}{12} \\ \\ = > S.P. \: = 10 \: and \: C.P. = 12$

When selling price is less than Cost Price then it will be loss.

Now,

$loss \: = S.P. - C.P. \\ \\ = > Loss = 12 - 10 = 2$

As we know that :

Loss% :

$\frac{Loss}{C.P.} \times 100 \\ \\ = > \frac{2}{12} \times 100 \\ \\ = > \frac{100}{6} = \frac{50}{3} \\ \\ = > 16 \frac{2}{3}$

So, the loss% will be 16.67%

Answer 2

Let each pen be re 1
sp of 12 pens =rs 12
cp of 10 pens = rs 10

but ,
sp of 12 pens = RS 10
CP of 10 pens = RS 12
L = cp -sp
= 12 -10
=2rs
L% = L×100/cp
=2×100/12
=50/3 %