Problems of the Week July 19 - 23, 2020

Jul 19, 2020 | Killarney

Solve the Problem of the Week for your grade level!

Get a Problem of the Week ballot and submit your entry before closing time on Thursday. All correct solutions will receive 5 extra punches on their Reward card at the start of their next session in the math learning centre. If you are using our online math tutoring platform, you can also submit your entry during your next online math learning session.

Grades 2-3: Grace plants a pea for her science fair project and measures how much it grows each week. The first week, it grows 2 centimetres. After 2 weeks, it is 5 centimetres tall. After 3 weeks, it is 9 centimetres tall. After 4 weeks, it is 14 centimetres tall. After 5 weeks, it is 20 centimetres tall. If the pattern continues, how tall will the pea plant be after 6 weeks?

Grades 4-6: Natalie collects water samples from 6 random puddles around her neighbourhood and counts the number of mosquito larvae in each. She finds 12, 22, 0, 13, 8, and 13 larvae in the samples. What is the average number of larvae per water sample that Natalie collected?

Grades 7-8: Bill’s science fair project is to test the different bacteria in the mouths of dogs and people. He swabs his own mouth and his dog’s mouth and then dabs a square centimetre of each in separate petri dishes. If the human mouth bacteria colony grows by a factor of 3 each day and the dog bacteria colony grows by a factor of 1.5 each day, then how much bigger will the area covered by the human bacteria be after 3 days?

Grades 9 and up: Luke makes a papier mache, right-circular-cone-shaped volcano model for his science fair project. The cone is 1.2 metres tall before he cuts off the top, which makes the volcano 2 decimetres shorter. If the area of the circular base of the cone is 144π square decimetres, then what is the volume of the volcano model after its top has been removed? (Hint: The volume of a cone is â…“ of the area of its base times its height.)