Quantitative Aptitude - Arithmetic Ability Questions

Case I :  MW  MW  MW  MW

Case II:  WM  WM  WM  WM

Let us arrange 4 men in 4! ways, then we arrange 4 women in 4P4 ways at 4 places either left of the men or right of the men. Hence required number of arrangements

   4! × 4P4 + 4! × 4P4 = 2 × 576 = 1152

Speed in still water = Average of Speed in Upstream and speed in Downstream

= 1/2 (12 + 6) kmph = 9 kmph.

Given compound interest for 3 years = Rs. 1513.2

and simple interest for 5 years = Rs. 2400

Now, we know that  C.I = P1+R100n - 1

=> 1513.2 = P1+R1003 - 1 ...........(A)

And S.I = PTR/100

=> 2400 = P5R/100 ..................(B)

By solving (A) & (B), we get

R = 5%.

Let the length of the wire be h. 

Radius  r =1/2 mm = 1/20 cm  

πr2h = 66  

=> h= (66 x 20 x 20) x (7/22) = 8400cm = 84m 

By trial and error method, when we substitute 

x = 0

Both LHS and RHS are equal.

Given the price of a commodity is decreased by  p = 20%

And its consumption is increased by q = 10%

Now, required increase or decrease in the expenditure on the commodity can be 

p + q + pq/100 = -20 + 10 - 200/100 = -10 - 2 = -12%.

Hence, decrease in the expenditure = 12%

Taking the 2 investments to be 3x and 5x respectively
Total income of Raghu = (3x) x 1.25 + (5x) x 0.9 = 8.25
Therefore, Gain% = 0.25/8 x 100 = 3.125 %.

Given total number of passengers in the bus = 45

First average weight of 45 passengers = 52 kgs

Average weight of 5 passengers who leave bus = 48

Average weight of 5 passengers who joined the bus = 54

Therefore, the net average weight of the bus is given by

$$\begin{gathered} = 45 x 52 - 5 x 48 + 5 x 5445 \\ = 237045 \\ = 1583 \\ = 52.66 kgs. \end{gathered}$$