Aptitude and Reasoning Questions

Second is the tool used by the first.

Let the leak will empty the tank in x hrs 

Then, 1/9 - 1/x = 1/13

x = 29.25 hrs

The number of days required by a single kirlosker pump to fill the tank = 6 x 7 =42 days and the number of days required by a single USHA pump to fill the same tank = 2 x 18 =36 days.

Now , since efficiency is inversely proportional to the number of days. Hence,

Efficiency of one K - pumpEfficiency of U- pump=3642=67  

Here the P is the wife of Q who is brother of T who is daughter of U.

That implies P is wife of U's son Q => U is father-in-law of P.

Given,Let the cost price of single book be Rs. 100.

The cost price of (9 + 1) = 10 pair i.e. 20 books = Rs. (100 × 20) = Rs. 2000.He gets profit of 26%.

So, the selling price of 9 pair i.e. 18 books = Rs. 2000 × (126/100) = Rs. 2520

Then,the selling price of single book = Rs. 2520/18 = Rs. 140

He gives 20% discount on the marked price of a book.

That means, when the selling price is Rs. 80 then the marked price is Rs. 100.

∴When the selling price of single book is Rs. 140, the marked price = Rs. 140 × (100/80) = Rs. 175

∴The percentage increase in marked price from the cost price = (175 –100)% = 75%

Let CP = 100,
42 % increase => SP = 142
10 % discount in SP => ((142 x 10)/100) = 14.2
So 1st SP = (142 - 14.2) = 127.8, again 12 % discount in 1st SP ((127.8 x 11)/100) = 14.058
2nd SP = (127.8 - 14.058) = 113.742,
So finally CP = 100, SP = 113.742, => gain = 13.742%.