Averages and Unitary Methods

Peter Farnum, St. People’s Cathedral School, Barbados

John wants to buy nine oranges. How much money does he need if one orange costs $0.75?

If I paid $15 for 30 eggs, how much would I pay for 9 eggs?

If 1 dozen magoes costs $18.00, how much would 16 mangoes cost?

If I bought 20 fish cakes for $18, how many fish cakes could I buy with $45?

A movie theatre seats patrons in rows of thirty seats each.  How many people can be seated in eight and a half rows?

A school hall seats a total of 900 students in 25 rows of chairs.  How many students can be seated in 12 rows?

1250 people are attending the Family Fun Day Picnic.  If each bus holds 30 people, how many buses must be chartered for event?

If one third of a number equals 15, what is the number?

If two-fifths of a number equals 20, what would be three-fifths of the same number?

60 is 5/6 of a number. What is the number?