Quantitative Aptitude - Arithmetic Ability Questions

$$\begin{gathered} ?2=400+16650x100 \\ ?= 8 \end{gathered}$$

From the given data,

When the price of rice is decreased by 10%, the value of Rs. 270 would become

270 x 100/90 = 300

Now, the value 270 becomes 300

And given, the girl could buy 1 kg extra for that value

Change in value = 300 - 270 = Rs. 30

Therefore, 1 kg extra rice she can get for Rs. 30

=> The original price of rice = Rs. 30/kg.

As she gets only 9 kgs for Rs. 270 before 10% discount, now after discount she gets 10 kgs instead of 9 kgs for Rs. 270.  

Let length, breadth and height of the room be 7, 3, 1 unit respectively.

Area of walls = 2(l+b)xh = 2(7+3)x1 = 20 sq. unit.

Now, length, breadth and height of room will become 3.5, 6 and 2 respectively. 

Area of walls = 2(l+b)xh = 2(3.5+6)x2 = 38 sq. unit. 

% Increase in the area of walls = (38-20)x100/20 = 90%.

4 persons can be selected from 9 in 9C4 ways =126

Fvaourable events =4C2*5C2 =60

So,required probability = 60/126 = 10/21

 $$\begin{gathered} = log 33 + log 23+ log 103log10×3×22 \\ \end{gathered}$$ 

=log33 12+log 23+log 10312log(10×3×22)  

=12log 33+3 log 2+12 log103log10+log3+log22  

=32log 3 + 2 log 2 + log 10log 3 + 2 log 2 + log 10 = 32