Jessica had a six-sided dice numbered from 1 to 6.
She rolled it 120 times.
a) If the dice were fair, how many times would you
expect it to have landed on 5?
b) Jessica recorded that the dice landed on 5 a
total of 21 times. Is the dice definitely biased or
definitely not biased, or is it impossible to tell?
Write a sentence to explain your answer.