SP - CP = 480

Correct Option: B

SP - CP = 480
1.2x - x = 480
⇒0.2x = 480
⇒x = 2400

So selling price SP = 2400 + 480 = 2880

SP at Profit - SP at loss = Rs 12

Correct Option: D

Let Cost Price (CP) = x
Then Selling Price(SP) if he sells at profit = x(1+8%) = 1.08x
and SP, if he sells at loss = x(1-8%) = 0.92%
Given, 1.08%-0.92% = Rs12
0.16x = Rs.12
⇒x = Rs.75

Assume as x be the amount of water added to make concentration of 50%

Correct Option: A

Concentration of Sulphuric acid = 80%
So in a 100cc, Sulphuric acid = 80cc and water = 20cc
Let x be the amount of water added to make concentration of 50%
⇒80/(100+x) = 50/100
⇒ 80/(100+x) = 1/2
∴ x = 60cc

Percentage of silver = weight of silver/ weight of alloy

Correct Option: C

Total weight of alloy = 20+20+ 40 = 80g
Weight of tin = 20g
Percentage of tin = 20g/80g x 100
=25%

Final price = Initial price x (1 + 1st increase in percent) x (1 + 2nd increase in percent)

Correct Option: A

Final Price = 25 x (1 + 20/100) x (1 + 40/100)
=Rs.25 x 1.2 x 1.4
= Rs. 42