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Boolean operators - Answers

Q1. For all questions:

s = 5

t = 10

u = 20

Boolean expression True or False?
s < u and u > t  True
t > s and s == 5  True
s != u and t != s  True
5 = s or t != 20 Error - using the assignment symbol 
not s == 5 False
not u > 10 False
s > 10 or u <= 20 True 
 u != 10 or t == 10 True
 t >= 5 and s == 10 or u < 10 False
 s >= 5 and not t == 10 False 
 not u <= 20 and t < 50 False
 s == 5 and t == 5 and u == 20 False
not s != 5 and not t != 5 False
(s != 5 or t == 10) and u != 30  True
(t == 10) or (u == 20)  True 
(not s != 10) or (not t != 10) True
u == 20 and not t < 30  False 
s > 1 or (u = 20 and t <= 10)  Error - using the assignment symbol
 (not s != 10) or (not t == 10) False 
 (not t != 10) and (not s != 5) True

 Q2. Students should be encouraged to predict answers before using Python. They should then check their answers with a friend's and try to work out why any differences occurred. Only then should they use Python to check their answers.

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