Quantitative Aptitude - Arithmetic Ability Questions

Draw the diagram. The diagonal of the rectangle is the diameter of the circle. The diagonal is the hypotenuse of a 3,4,5 triangle and is therefore, 5.

Circumference = π.diameter = 5π

Side of smallest cube = L.C.M of 5, 10, 20 = 20cm  

Volume of the cube = (20 x 20 x 20)cu.cm = 8000 cu.cm  

Volume of the block= (5 x 10 x 20)cu.cm = 1000 cu.cm  

Number of blocks = (8000/1000) = 8

Let the mother's present age be x years.

Then, the person's present age = 2/5 x years.

(2x/5 + 8) = 1/2 (x + 8)

2(2x + 40) = 5(x + 8) => x = 40.

The CP of profitable cow  = 9900/1.1 = 9000

and profit = Rs. 900

The  CP of loss yielding cow = 9900/0.8 = 12375

and loss = Rs. 2475

so, the net loss = 2475 - 900 = 1575

m+nm-n=7xx ⇒mn=4x3x  

Again   mn=12x2 

and         mn =60x  

so, 60x=12x2 ⇒x=5    

=>  m= 20  and    n= 15

Hence,    1m:1n=120:115=3:4

let x and y be the sides of the rectangle then 

correct area =105100x×96100y 

Error% = 504500xy-xy=4500xy %

4500xy×1xy×100=45=0.8