a) At a sale, Sarah spent $143 on some shirts and shorts. The shirts cost $15 each and the shorts cost $17 each. What is the total number of shirts and shorts that Sarah bought?

b) Bill sits for a test containing 20 questions. He gets 2 marks for each correct answer and loses 1 mark for each incorrect answer. He scored 22 marks in the test. How many questions did he get correct?

c) Fred is twice as old as his son and Fred is 36 years older than his son. How old is Fred?

d) Mina earns $3600 more than Betty and Lina earns $2000 less than Betty. If the total of the three incomes is $151 600, find the incomes of each person.