After several defeats in wars, Robert Bruce went in exile and wanted to commit suicide. Just 

before committing suicide, he came across a spider attempting tirelessly to have its net. Time 

and  again,  the  spider  failed  but  that did not  deter  it to refrain from making attempts. Such 

attempts  by  the spider  made  Bruce  curious. Thus,  Bruce  started observing the nearimpossible

goal of the spider to have the net. Ultimately, the spider succeeded in having its net despite several 

failures. Such act of the spider encouraged Bruce not to commit suicide. And then, Bruce went 

back again and won many a battle, and the rest is history. Which one of the following assertions 

is best supported by the above information?

The current erection cost of a structure is Rs. 13,200. If the labour wages per day increase by 

1/5 of the current wages and the working hours decrease by 1/24 of the current period, then the

 new cost of erection in Rs. is

Find the sum of the expression 

`1/(sqrt(1) + sqrt(2))` + `1/(sqrt(2) + sqrt(3))` + `1/(sqrt(3) + sqrt(4))`  +..... +`1/(sqrt(80) + sqrt(81))`

A tourist covers half of his journey by train at 60 km/h, half of the remainder by bus at 30 km/h and the rest by cycle at 10 km/h. The average of the tourist in km/h during his entire journey is  

Out of all the 2-digit integers between 1 and 100, a 2-digit number has to be selected at random. 

What is the probability that the selected number is not divisible by 7?