: In an class there are M students , except 20 all are above 15 years of age. 30 students are below 15 . What is the value of M ?

a) 30
b) 35
c) 50
d) data insufficient
e) none of these

• none of these
  
• 11 years agoHelpfull: Yes(3) No(0)
• data insufficient
  because in first statement 20 are below 15 but in second statement 30 below 15
  so this is not possible
  
  thank you
• 11 years agoHelpfull: Yes(0) No(0)