A book was sold for Rs 27.50 with a profit of 10%. If it were sold for Rs. 25.75, then would have been percentage of profit and loss ?

Answer: Option A

Explanation:

This type of question can be easily and quickly solved as following:

Let at Rs x it can earn 15% pr0fit
85:18700 = 115:x [as, loss = 100 -15, Profit = 100 +15]

x = (18700*115)/85
= Rs.25300

Answer: Option D

Explanation:

So we have C.P. = 27.50
S.P. = 28.60

Gain = 28.60 - 27.50 = Rs. 1.10

\begin{aligned}
Gain\% = \left( \frac{Gain}{Cost} * 100 \right)\% \\
= \left( \frac{1.10}{27.50} * 100 \right)\% = 4\%
\end{aligned}

Answer: Option C

Explanation:

So before solving this question we will get the C.P. and S.P. of 1 article to get the gain percent.

C.P. of 1 orange = 350/100 = Rs 3.50
S.P. of one orange = 48/12 = Rs 4 [note: divided by 12 as 1 dozen contains 12 items]
Gain = 4 - 3.50 = Rs 0.50
\begin{aligned}
Gain\% = \frac{0.50}{3.50}*100 \\
= \frac{100}{7}\%
= 14\frac{2}{7}\%
\end{aligned}

Answer: Option C

Explanation:

Let original Cost price is x
Its Selling price = 105/100 * x = 21x/20
New Cost price = 95/100 * x = 19x/20
New Selling price = 110/100 * 19x/20 = 209x/200
[(21x/20) - (209x/200)] = 1

=> x = 200

Answer: Option D

Explanation:

Let the Cost Price of one article = Rs. 1
CP of x articles = Rs. x
CP of 20 articles = 20
Selling price of x articles = 20

Profit = 25% [Given]

\begin{aligned}
\Rightarrow \left (\dfrac{SP - CP }{CP}\right ) = \dfrac{25}{100} = \dfrac{1}{4}

& \Rightarrow \dfrac{\left(20-x \right )}{x} = \dfrac{1}{4} \\
& \Rightarrow 80 - 4x = x \\
& \Rightarrow 5x = 80 \nonumber \\
& \Rightarrow x = \dfrac{80}{5} = 16 \\

\end{aligned}