70% respond badly:
20 + 30x0 + 1 =?

ONLY FOR GENIUS:
10 + 10x0 + 20x1 + 5x0+ 3
¿Can you solve this?

D + A = 50
A + A + A = 120
D + C = 35
C = ?

Only few can solve it:
11 x 11 = 4
22 x 22 = 16
33 x 33 =?

Mary is 3 years old, David is twice her age, when David will have 60
how old Mary will have? 

My age today is three times what it will be three years from now minus three times what my age was three years ago. 
How old am I?

Only for genius:
C + C + C = 30
C + O = 40
C + O + P = 60
P = ?

77x = 189x = 345x 

¿Which is the value of x?

At college, 70% of the students studied Maths, 75% studied English, 85% studied French and 80% studied German.
What percentage at least must have studied all 4?

D + A = 50
A + A + A = 120
D + C = 35
C = ?

81% fails:
98-15x10 + 50 =?

Viral challenge

2 + 2 (2 + 2 x 0) + 2x0 = ?

A) 8     B) 6    C) 2    D) 0