Exams

area of the plot = 120m x 60m = 7200 sq.m
area of plot excluding gravel = 117m x 57m = 6669 sq.m
area of gravel = 7200 sq.m - 6669 sq.m = 531 sq.m
cost of building it = 531 sq.m x 65 ps = 34515 ps
In Rs. = 34515/100 = Rs. 345.15.

Let the speed of current = 'C' km/hr

Given the speed of boat in still water = 6 kmph

Let 'd' kms be the distance it covers.

According to the given data,

Boat takes thrice as much time in going the same distance against the current than going with the current

i.e, d8 - C = 3 × d8 + C

$$\begin{gathered} ⇒ 24 - 3C = 8 + C \\ ⇒ 4C = 16 \\ ⇒ C = 4 kmph \end{gathered}$$

Hence, the speed of the current C = 4 kmph.

Given, 

25% of three-seventh of 26% of a number is 145.5

Let the required number be 'N'

i.e, 25100x37x26100xN = 145.5

N = 145.5x7x1000075x26

=> N = 5223.07

For 30 days he receives

30 x 25 = 750
               

Actually he gets 425

Therefore, Fine is 750 - 425 =  325

=> No of days absent = 325/(25+7.50)= 10

The longest-surviving dynasty in the world is the Imperial House of Japan.

Total no of ways = (14 – 1)! = 13!

Number of favorable ways = (12 – 1)! = 11!

So, required probability = 11!×3!13! = 39916800×66227020800 = 24625