At kul - kul petrol pump the operator gives 5% less petrol but he sells it at the cost price.What is his profit in this way?

Its simple i.e. 25% nothing else, which is very obvious

Loss % = ( common gain or loss / 10 )² %
= (20 / 10)² %
= 4%

Now assume total CP of both articles be x, then SP = 0.96x = 400
x = 400 / 0.96 = CP

loss = 4% of CP
= (4 / 100) X (400 / 0.96) = Rs. 16.66

Loss % = ( common gain or loss / 10 )² %
= (20 / 10)² %
= 4%

CP / SP = 29x / 19x
loss % = 29x - 19x / 29x X 100 = 34.48 %

(To understand the concept assume CP of each article Rs 29 and SP of each article = Rs. 19)

Go through option C

180 x 12 x 1.2 + 180 x 8 x 1.1 = 180 [ 14.4 + 8.8 ]
= 180 (23.2) = 4176

And 180 x 20 x 1.15 = 4140

Therefore loss = 4176 - 4140 = 36
Hence option (c) is correct

6.66% of MP = 25
? MP = 375
? SP = MP - 25 = 350

Abhishek Discount = 2800
Bhanu Discount =2400+640=3040

The difference in selling price is same as difference in discount = 3040 - 2800 = Rs.240

From the question
10 % x = 15% of y ...(i)
x+y = 30000 ...(ii)

from eq. (i)
x / y = 3/2 ...(iii)

by solving eq. (ii) & (iii)
x = 18000, y = 12000

Hence, the difference =6000

Let the cost price of 1 litre pure milk be Rs. 1, then
for 6 litres (milk) CP = Rs. 6
for 2 litres (Water) CP = Rs. 0

and for 8 litres mixture SP = 8 x 2 = Rs.16

Profit = [(16-6) / 6] x 100 = 1000 / 6 = 166.66 %

Initially :
CP =100
SP = 140 (Since profit = 40 %)

New price :
CP =100
SP = 140 - 20% = 112
MP = 140

Profit % = [(112 - 100 )/100] = 12 %