7
Q:

 A) 9 B) 5 C) 4 D) 6

Explanation:

Looking at the diagram in  rows, the central circle equals half the sum of the numbers in the other circles to the left and right of the centre.

Looking at the diagram in rows, the central circle equals half the sum of the numbers in the other circles to the left and right of the centre. - See more at: http://www.theonlinetestcentre.com/number-puzzles.html#1
Subject: Number Puzzles
Q:

What mathematical symbol can be placed between 5 and 9, to get a number greater than 5 and smaller than 9?

decimal point [i.e, 5.9]

Subject: Number Puzzles

1642
Q:

Find a 10-digit number, where the first figure defines the count of zeros in this number, the second figure the count of numeral 1 in this number etc. At the end the tenth numeral character expresses the count of the numeral 9 in this number.

Sum of all numerals must be ten because each numeral stands for the count of other numerals and because this number shall have ten numerals. Beginning to choose reasonable numerals for the first figure you can come across the correct number: 6210001000.

Subject: Number Puzzles

1460
Q:

Can you arrange 9 numerals - 1, 2, 3, 4, 5, 6, 7, 8 and 9 [using each numeral just once] above and below a division line, to create a fraction equaling to 1/3 [one third]?

$\inline \frac{5832}{17496}=\frac{1}{3}$

Subject: Number Puzzles

1832
Q:

Find the missing Number?

How ?

7*6 = 4 2
9*9 = 8 1
5*3 = 1 5
6*2 = 1 2

Subject: Number Puzzles

2727
Q:

 A) 90 B) 56 C) 34 D) 104