Practice Test: Number Series- 2

In this simple subtraction series, each number decreases by 0.4.

The pattern is 
4*2+1=9 
9*2+1=19 
19*2+1=39 
39*2+1=79 
79*2+1=159 
 

2*3 = 6
6*3 = 18
18*3 = 54
54*3 = 162

Each number increases by 2.
Like -
First number is 2
Second number = 2 + 2 =4
Third number = 4 + 2 = 6
Fourth number = 6 + 2 = 8
Fifth number = 8 + 2 = 10  and
Sixth number = 10 + 2 = 12
Hence, The answer is (b) 12.

This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.

In this simple addition series, each number increases by 0.8.
Next number will be 4.7

The series is 14, 28, 20, 40, 32, 64
Take three terms at a time. The notation be as follows:-
Let, First term = a = 14
It is evident that Second term= 2*a = 2 * 14 = 28 and,
The Third term = Second term - 8 OR ( 2*a - 8 ) = 28 - 8 = 20
Now consider the third, fourth and the fifth term.
Let, Third term = a = 20
It is evident that Fourth term= 2*a = 2 * 20 = 40 and,
The Fifth term = Second term - 8 OR ( 2*a - 8 ) = 40 - 8 = 32
Similarly consider fifth, sixth and the seventh(term to be found).
Let, Fifth term = a = 32
It is evident that Sixth term = 2*a = 2 * 32 = 64 and,
The Seventh term ( term to calculated) = Second term - 8 OR ( 2*a - 8 ) = 64 - 8 = 56
 

In this addition series, 1 is added to the first number; 2 is added to the second number; 3 is added to the third number; 4 is added to the fourth number; and go on.

This is a simple subtraction series.
Each number is 35 less than the previous number.
(544 - 35 = 509) (509 - 35 = 474) (474 - 35 = 439) (439 - 35 = 404)...

8 x 1 - 2 = 6
6 x 2 - 3 = 9
9 x 3 - 4 = 23
23 x 4 - 5 = 87
87 x 5 - 6 = 429