Quantitative Aptitude - Arithmetic Ability Questions

Weekend means Saturday & Sunday together. In total we have 52 weeks in a year. So there are 52 weekends in a year.

In normal we have 104 Weekend Days.

 We know that a Each normal year has 365 days or 52 weeks plus one day, and each week has two weekend days, which means there are approximately 104 weekend days each year.
Whereas in a leap year we have 366 days it adds one more day to the year. And what makes the change is the starting day of the year.

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

The series follows the following pattern

5 X 5 – 5 = 20

20 X 4 – 4 = 76

76 X 3 – 3 = 225

225 X 2 – 2 = 448

Hence, the term 225 denoted by (d) completes the series

given

 48?+32?= 320 

=> 6?+4?=40

Now squaring on both sides

=> 36 x ? + 16 x ? + 48 x ? = 1600

=> 100 x ? = 1600

=>  ? = 16

Gain % = 100+common gain %2100-100%           

           =100+102100-100

            = 21%

 22 = 2 x 11

 54 = 2×33

108 = 22×33

135 = 33×5 

198 = 2×32×11

 ∴ L.C.M = 22×33×5×11=5940