Quantitative Aptitude - Arithmetic Ability Questions

Let the breadth of the wall be x metres. 

Then, Height = 5x metres and Length = 40x metres.  

x * 5x * 40x = 12.8   

=>x3 =12.8/200 = 128/2000 =64/1000  

=> x = 4/10 m  

=> x = (4/10)*100 = 40 cm

In one hour, the minute hand gains 330° over the hour hand. i.e., 60 minute, the minute hand gains 330° over the hour hand.

∴ In 16 minutes, the minute hand gain over the hour hand by

 Draw BE // CD

Then, CE = AB = 1.6 m,

BE = AC =

 $$\begin{gathered} DEtan30 \\ => DE = tan30 x 203 \\ => DE = 13x203 = 20 \end{gathered}$$

Therefore, CD = CE + DE = (1.6 + 20) m = 21.6 m.

Speed in still water = 6 kmph

Stream speed = 1.2 kmph

Down stream  = 7.2 kmph

Up Stream = 4.8 kmph

x/7.2 + x/4.8 = 1

x = 2.88

Total Distance  = 2.88 x 2 = 5.76 kms

Other number = 11×7700275= 308

1/8 - 1/x = 1/10

 => x = 40 hrs

Each of the 10 letters can be posted in any of the 5 boxes.

So, the first letter has 5 options, so does the second letter and so on and so forth for all of the 10 letters.

i.e. 5*5*5*….*5 (upto 10 times) = 5 ^ 10.