Quantitative Aptitude - Arithmetic Ability Questions

Let the required numbers be 33a and 33b. 

Then 33a +33b= 528   =>   a+b = 16.

Now, co-primes with sum 16 are (1,15) , (3,13) , (5,11) and (7,9).

Therefore, Required numbers are  ( 33 x 1, 33 x 15), (33 x 3, 33 x 13), (33 x 5, 33 x 11), (33 x 7, 33 x 9)

The number of such pairs is 4

Given number series is 61, 66, 83, 121, 185

Here the given series follows a pattern that,

$$\begin{gathered} 61 \\ 61 + 22 + 1 = 66 \\ 66 + 42 + 1 = 83 \\ 83 + 62 + 1 = 120 (not 121) \\ 120 + 82 + 1 = 185 \end{gathered}$$

Hence, the odd man in the given series is 121.

Here the given number series is 5  11  21  44  ?  175

Now the given series follows a pattern, that

x2 + 1, x2 - 1, x2 + 2, x2 - 2, x2 + 3, x2 - 3,...

Then the missing number is x2 - 2

= 44 x 2 - 2 = 88 - 2 = 86

Hence, the missing number in the number series is 86.

To be together between 9 and 10 o'clock, the minute hand has to gain 45 min. spaces.
55 min. spaces gained in 60 min.

45 min. spaces are gained in 6055×45 min  or 49111min