A survey has been conducted in a college on using the type of pen for writing. the results are as follows
Total number of ball pen users= 85
Total number of ink pen users= 105
Total number of gel pen users=125
No. Of students who use both ink pen and ball pen but no gel pen= 10
No. Of students who use both ball pen and gel pen but no ink pen=20
No. Of students who do not use ink pen or gel pen=75
No. Of students who do not use any or use all three=30

1) How many students use at least one of the three type of pens
a)215 B)245 C)275 D)270 e) 250

2) How many students use ball pens or both ink pen and gel pen only ?
a)90 b ) 110 c) 80 d) 85 e) 115

3) How many students use both ball pen and ink pen?
a)15 b) 25 c)20 d)30 e) none of these

4) How many students use all the three type of pen and none??
a)15,15 b)10,20 c)20,10 d)5,25 e) 30,0

5) What is the difference in the number of students who use at least two and the one who use at least one o f the three?
a)180 b)190 c)210 d)165 e) 150


Please explain in detail.