Analysis and Approaches for IBDP Maths Ebook 1 | Page 276

Your Practice Set – Analysis and Approaches for IBDP Mathematics
2. Sandy goes to work five days a week. On any day, the probability that she goes on a bus
is p .
(a)
(b)
Write down an expression, in terms of p , for the probability that she goes to
work on a red bus on exactly four days.
[2]
Hence, find the values of p such that the probability that she goes to work on a
red bus on exactly four days is 0.3.
[3]
3. The probability of obtaining “tails” when a biased coin is tossed is q . The coin is tossed
ten times.
(a)
(b)
Write down an expression, in terms of q , for the probability of obtaining at least
nine tails.
[2]
Hence, find the value of q such that the probability of obtaining at least nine tails
is 0.09.
[3]
4. There are one hundred customers in a café in a particular day. The probability that a
customer buys chocolate muffins is q .
(a)
(b)
Write down an expression, in terms of q , for the probability that there are at most
one customer buying chocolate muffins.
[2]
Hence, find the value of q such that the probability that there are at most one
customer buying chocolate muffins is 0.03.
[3]
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