Quantitative Aptitude - Arithmetic Ability Questions

The given series is 12, 48, 168, 502, 1260

12

12 x 4 = 48

48 x 3.5 = 168

168 x 3 = 504

504 x 2.5 = 1260

Hence, the odd man out in the given series is 502.

51 + 52 + 53 + ...........+ 100

 = (1 + 2 + 3 + .... + 100) - (1 + 2 + 3 + ...... + 50)

 = It is in the form of n(n+1)2 series summation

= n1 = 100 , n2 = 50

=100100+12 - 5050+12

 =  (5050 - 1275) = 3775

Next number of the sequence 1, 4, 12, 32,...

1 = 2 x 20

4 = 2 x 21

12 = 3 x 22

32 = 4 x 23

80 = 5 x 24.

Here the given series follows a pattern that, multiplying the number with odd numbers in decreasing order starting with 13. That is,

6 × 13 = 78

65 × 11 = 858

858 × 9 = 7722

7722 × 7 = 54054

54054 × 5 = 270270

Hence, the wrong number is 54055

Let the total profit be Rs. z. Then,

B's share = Rs. 2z/3,  A's share = Rs. ( z - 2z/3 ) = Rs. z/3.

A : B = z/3 : 2z/3 = 1:2

Let the total capital be Rs, X and suppose B's money was used for x months. Then.

(1(x) / 4 * 15) / (3x) / 4 * y) = 1/2 <=> y = (15 * 2 / 3) = 10 .

 Thus, B's money was used for 10 months.

 Since the month begins with a Sunday, so there will be five Sundays in the month,

Required average = (510 * 5 + 240 * 25) / 30 = 8550/30 = 285.