Quantitative Aptitude - Arithmetic Ability Questions

Given series is 

12        16         32          68         ?

Here it follows a pattern that,

12

12 + (2x2) = 16

16 + (4x4) = 32

32 + (6x6) = 68

68 + (8x8) = 132

One way to deal with fractions is to convert them all to decimals. 

In this case all you would need to do is to see which is greater than 0.5.

Otherwise to see which is greater than ½, double the numerator and see if the result is greater than the denominator. In B doubling the numerator gives us 8, which is bigger than 7. 

Here the given series 28, 12, 4, 2, -2 follows a pattern that

$$\begin{gathered} 28 \\ 28 - 24 = 28 - 16 = 12 \\ 12 - 23 = 12 - 8 = 4 \\ 4 - 22 = 4 - 4 = 0 (NOT 2) \\ 0 - 21 = 0 - 2 = -2 \end{gathered}$$

Hence, the odd man in the given series is 2.

Let the cost price of 1-liter pure milk be Re.1, then 

 6 liters (milk) → C.P = Rs. 62 liters (water) → C.P = Rs. 0→CP = Rs.6 only

8 litre mixture  =>

SP =>  8 x 2 = Rs. 16

Profit % = 16 - 66x100 = 10006 = 166.66%

This can be easily simplified by Approximation process

Given 39.96% of 649.85 ÷13.07 = 45.14 - ? can be written as 

40% of 650 ÷13 = 45 - ?

$$\begin{gathered} 40 x 65010013 = 45 - ? \\ ? = 45 - 20 \\ ? = 25. \end{gathered}$$

Let there be x voters and k votes goes to loser then 

      0.8x - 120 = k + (k + 200)

         k+200 = 0.41x

 => k = 1440

and  (k + 200) =1640

Therefore  1440/3200 x 100 = 45%

Let the side of the square(ABCD) be x meters.

Then, AB + BC = 2x metres.

AC = 2x = (1.41x) m.

Saving on 2x metres = (0.59x) m.

Saving % =0.59x2x*100 = 30% (approx)

The given number series follows a pattern that,

56

56 + 8 = 64

64 - 16 = 48

48 + 32 = 80 (Not equal to 90)

80 - 64 = 16

16 + 128 = 144 

Hence, the odd number in the given number series is 90.