Puzzle 7:- What number should replace the question mark?

Ans:-9.

Sol:-The number at the centre of each triangle equals the sum of the lower two numbers minus the top number.

Puzzle 8:- What number should replace the question mark?

Ans:-3.

Sol:-A+B=76 and A-B=38 then

A=57 And B=19

A/B=57/19=3

A=57 And B=19

A/B=57/19=3

Puzzle 9:- What number should replace the question mark?

Ans:-1.

Sol:-Multiply the bottom two numbers then take the square root, i.e.

1×4 = 4 and √4 = 2.

1×4 = 4 and √4 = 2.

Puzzle 10:- What number should replace the question mark?

Ans:-10.

Sol:-Each diagonal line of numbers, starting with the top left hand corner number, increases by 1 each time.

Example

4

2+3=5

2+1+3=6

2+1+2+2=7

4+1+3=8

5+4=9

10

Example

4

2+3=5

2+1+3=6

2+1+2+2=7

4+1+3=8

5+4=9

10