A

Initial amount spent on trouser by the man = Rs. 1250
Now, by the reduction of 20% in 1250, he can buy t-shirt too.
[latex]\Rightarrow[/latex] t-shirt cost = 20% of 1250 = 20 x [latex]\frac {1250}{100}[/latex] = 250
Therefore, the price of the t-shirt = Rs. 250.

B

Let the marked price of the router be Rs. P
From the given data,
p [latex]\times \frac {85}{100} - P \times \frac {80}{100} = 51[/latex]
p [latex]\times \frac {5}{100} = 51[/latex]
[latex]\Rightarrow P = \frac {5100}{5} = 1020[/latex]
Hence, the original marked price of the router is Rs. 1020.

A

Let cost of each cell phone = Rs.100 & Sale = 100 phones.
Money receipt = Rs.(100 x 100) = Rs.10,000
New cost per cellphone = Rs.120 and New sale = 70 phones
New Money Receipt = Rs.(70 x 120) = Rs.8400
Then the effect of sales = decrease in money receipt = [latex]\frac {1600}{10000} \times 100 = 16 %[/latex]

B

Let the cost price of 1 article = Rs. 1
From the given data,
Then, the selling price of 1 article = [latex]\frac {22}{18} = \frac {11}{9}[/latex]
Then, Profit = SP - CP = [latex]\frac {11}{9} - 1 = \frac {2}{9}[/latex]
Required, profit % = Profit/CP x 100
= [[latex]\frac {(\frac {2}{9})} {1} [/latex]] x 100
= 200/9
= 22.222%.

B

Cost price = Rs. 30
Selling price = Rs. 50
Gain = Rs. 20
Profit % = Gain/cost price x 100 = 20/50 x 100 = 40%
[latex]\frac {Gain}{cost price} \times 100 = \frac {20}{50} \times = 40%[/latex]