Quantitative Aptitude - Arithmetic Ability Questions

Two men, three women and one child can be selected in ⁴C₂ x ⁶C₃ x ⁵C₁ ways = 600 ways.

Let the original price of the cycle be 100. After the first reduction the price will be 75.

This new price is then reduced by 20% = 0.8 x 75 = 60

60 represents a reduction of 40 percent on the original.

In this type of question, we will first calculate the distance covered in given time.

Distance covered will be : Number of revolutions x Circumference 

So we will be having distance and time, from which we can calculate the speed. 

Radius of wheel = 70 / 2 = 35 cm

Distance covered in 40 revolutions will be 40*circumferene=40*2πr=40*2*227*35=8800cm = 88 m

Distance covered in 1 sec  = 8810=8.8m/s=8.8*185km/hr=31.68km/hr

Take a square of side 4cm and a rectangle having l=6cm and b=2cm

then perimeter of square = perimeter of rectangle

area of square = 16 sq.cm

area of rectangle = 12 sq.cm

Hence a >b

In a 3 digit number one’s place can be filled in 5 different ways with (0,2,4,6,8)

10’s place can be filled in 10 different ways

100’s place can be filled in 9 different ways

There fore total number of ways = 5X10X9 = 450

Let the ratio be 'R'

Total number of students = 1050

Then,

9R + 5R = 1050

14R = 1050

=> R = 75

Hence, the number of boys = 9R = 9 x 75 = 675

Choose 1 person for the single room & from the remaining choose 2 for the double room & from the remaining choose 4 people for the four person room, 

 Then, ⁷C₁ x ⁶C₂ x ⁴C₄ 

_{= 7 x 15 x 1 = 105}

By mistake = x/10 

Actual value = x * 10 

% Change = 10x-x1010x×100 = 99100×100  = 99% (negative)

Since actual value is greater than the wrong value.