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.

Let the numbers be x, x + 1, x + 2,  x + 3, x + 4, x + 5 and x + 6,

Then   (x + (x + 1) + (x + 2) + (x + 3) + (x + 4) + (x + 5) + (x + 6)) / 7 = 20.

or  7x + 21 = 140 or 7x = 119 or x =17.

Latest number = x + 6 = 23.

114       131     165     216     ?      369

   +17      +34     +51     +68    +85

=> The missing number in the given Number series = 216 + 68 = 284.

The terms are alternatively multiplied by 1.5 and divided by 3. However, 18.5 does not satisfy it.

Clearly, n(S) = (6 x 6) = 36.

Let E = Event that the sum is a prime number.

Then E= { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4,3),(5, 2), (5, 6), (6, 1), (6, 5) }

n(E) = 15.

P(E) = n(E)/n(S) = 15/36 = 5/12.

55.55 + 155 + 15.55 + 0.5 + 0.05 = ?

 55.55

155.00

 15.55

   0.5

   0.05

_______

226.65

_______

Hence, the value of the given equation 55.55 + 155 + 15.55 + 0.5 + 0.05 = 226.65.