Quantitative Aptitude - Arithmetic Ability Questions

The given number series 2, 19, 0, 21, –2, ? follows a pattern,

2

2 + 17 = 19

19 - 19 = 0

0 + 21 = 21

21 - 23 = -2

-2 + 25 = 23

Hence, the next number in the series is 23.

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

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

 Let the numbers be 37a and 37b. Then , 37a x 37b =4107  => ab = 3.

 Now co-primes with product 3 are (1,3)

 So, the required numbers are (37 x 1, 37 x 3) i.e, (37,111).

 Therefore, Greater number = 111.

Let the price of the mixed variety be Rs. x per kg. By the rule of alligation, we have :

Cost of 1 kg of type 1 rice           Cost of 1 kg of type 2 rice  

∴(20-x)/(x-15) = 2/3 

⇒ 60 - 3x = 2x - 30

 ⇒ x = 18.