Quantitative Aptitude - Arithmetic Ability Questions

The series given follow the pattern

+2, +2+4, +2+4+6, +2+4+6+8, +2+4+6+8+10,...

Here ? = 7 + 2 + 4 = 13.

Average = total runs / no.of innings = 32 

So, total = Average x no.of innings = 32 x 10 = 320.

Now increase in avg = 4runs. So, new avg = 32+4 = 36runs 

Total runs = new avg x new no. of innings = 36 x 11 = 396 

Runs made in the 11th inning = 396 - 320 = 76

Let the son's present age be x years .Then, (38 - x) = x => x= 19. 

Son's age 5 years back = (19 - 5) = 14 years

On 31st December, 2005 it was Saturday. 

Number of odd days from 2006 to 2009 = (1 + 1 + 2 + 1) = 5 days. 

On 31st December 2009, it was Thursday.

Thus, on 1st Jan, 2010 it is Friday

Here the given number series is 3, 14, 36, 67, 113, 168

It follows a pattern that

3

3 + 1 x 11 = 3 + 11 = 14

14 + 2 x 11 = 14 + 22 = 36

36 + 3 x 11 = 36 + 33 = 69

69 + 4 x 11 = 69 + 44 = 113

113 + 5 x 11 = 113 + 55 = 168

Hence, the wrong number is 67.

We have n(s) =52C2 52 = 52*51/2*1= 1326. 

Let A = event of getting both black cards 

     B = event of getting both queens 

A∩B = event of getting queen of black cards 

n(A) = 52*512*1 = 26C2 = 325, n(B)= 26*252*1= 4*3/2*1= 6  and  n(A∩B) = 4C2 = 1 

P(A) = n(A)/n(S) = 325/1326;

P(B) = n(B)/n(S) = 6/1326 and 

P(A∩B) = n(A∩B)/n(S) = 1/1326 

P(A∪B) = P(A) + P(B) - P(A∩B) = (325+6-1) / 1326 = 330/1326 = 55/221

52000 ÷ 40 ÷ 65 × 30 = ? - √400

(52000 ÷ 40) ÷ 65 × 30 = ? - 20

(1300 ÷ 65) × 30 = ? - 20

20 × 30 = ? - 20

600 = ? - 20

? = 620