Aptitude and Reasoning Questions

Let the sum be Rs. P
P{ 1+81002- 1 } = 2828.80

It is in the form of  a2-b2 = a+ba-b

P(8/100)(2 + 8/100) = 2828.80

P = 2828.80 / (0.08)(2.08)

= 1360/0.08 = 17000

Principal + Interest = Rs. 19828.80

From I and II. we conclude that Mathematics period began at 9.00 a.m., Biology period began at 8.00 a.m. and Physics period began at 11 a.m. So. the Chemistry period began at 10.00 a.m. From I and III, we conclude that Mathematics period ended and Chemistry period began at 10.00 a.m.  

This would not mean that K and L will always be together. It just implies that, if K is there, then L will also be there.

At the same time, it can happen that L is there but K isn't.

Remember, the condition is on K, not on L.

Exact interest, I= prt = $8000 × 0.085 × 90/365 = 167.67

Ordinary Interest, I= Prt = $8000 x 0.085 x 90/360 = 170

Let marks obtained by N = x

M's marks = 0.80x

L's marks = 1.25 (0.80x)

K's marks = (0.90) (1.25) (0.80x)

= 0.9x

But 0.9x = 360 ⇒ x = 400

Percentage of Marks obtained by N

= 400 x 100/500 = 80%

let original radius = r and  new radius = (50/100) r = r/2

original area = πr2 and new area = πr/22

decrease in area =  3πr2/4*1πr2 *100 = 75%

80x900/100 + 256 x 4 x ? = 1331 - 99

720 + 1024 x ? = 1232

? = 1232 - 720/1024

? = 512/1024 = 0.5

? = 0.5 

Time taken by one tap to fill half of the tank = 3 hrs.

Part filled by the taps in 1 hour = 4 x 1/6 = 2/3

Remaining part = 1 - 1/2 = 1/2

2/3 : 1/2 :: 1 : p

p = 1/2 x 1 x 3/2 = 3/4 hrs. i.e., 45 min

So, total time taken = 3 hrs 45 min.