If the cost price of 12 pens is equal to the selling price of 8 pens, the gain percent is ?

Answer: Option D

Explanation:

85 : 9 = 105 : x
x= (9×105/85)
= Rs 11.81

Answer: Option A

Explanation:

Let C.P.= Rs. 100.
Then, Profit = Rs. 320,
S.P. = Rs. 420.

New C.P. = 125% of Rs. 100 = Rs. 125
New S.P. = Rs. 420.

Profit = Rs. (420 - 125) = Rs. 295

Required percentage = (295/420) * 100
= 70%(approx)

Answer: Option C

Explanation:

Let the new S.P. be x, then.
(100 - loss%):(1st S.P.) = (100 + gain%):(2nd S.P.)

\begin{aligned}
=>\left( \frac{95}{1140} = \frac{105}{x} \right) \\

=> x = 1260
\end{aligned}

Answer: Option A

Explanation:

Please note in this type of questions, get the value of 1 kg to solve this question, lets solve it.

C.P. of 1 Kg = 420/70 = Rs. 6
Selling Price = 6.50
Gain = Rs. 0.50

\begin{aligned}
Gain\% = \frac{.50}{6}*100 \\
= 8\frac{1}{3}\%
\end{aligned}

Answer: Option C

Explanation:

As question states that rate was of pair of articles,

So rate of One article = 37.40/2 = Rs. 18.70

Let Marked price = Rs X
then 85% of X = 18.70

=> X = 1870/85 = 22