Sequences and Regularities

Find the number of white balls that the next sequence will have.

• 18

• 21

• 22

• 23

Find the next number:

1, 3, 6, 10, 15, 21, ...

• 28

• 29

• 25

• 30

What is the general term of the following numerical sequence: 3, 12, 21, 30, 39, ... ?

• 5n-2

• 2n+1

• 10n-7

• 9n-6

The following figure represents the first three terms of a sequence.

The first five termes of the sequence are:

• 3, 5, 7, 9 and 11

• 4, 5, 6, 7 and 10

• 7, 10, 12, 13 and 14

• 3, 5, 7, 9 and 10

The following figure shows the first four terms of a sequence of circles and squares.

Which of these expressions represents the number of squares of a term of order n?

• 2n

• n+1

• 4n+3

• n-1

What is the next term of the sequence: 23;29;35....

• 40

• 46

• 41

• 39

What are the 3 terms of the following sequences: 10;20;30?

• 10; 30; 50

• 40; 50; 60

• 28; 37; 18

• 35; 17; 27