100 students were asked if they study French or Spanish.
55 of these students are in Year 10, the rest are in Year 11. 12 of the Year 10 students study Spanish. 70 of the 100 students study French.
a.[3]
Use this information to complete the frequency tree.
b.[2]
One of the students who study Spanish is chosen at random.
Write down the probability that this student is in Year 11.