Problems of the Week - January 11 to January 16

Rewards for Problems of the week:

5 points for the correct answer at your level; 10 points for the next level; 20 points each for 2+ levels up.

Lower Elementary:

Question: A shark eats 10 fish on Monday, 9 fish on Tuesday, 8 fish on Wednesday, and so on. If the pattern continues, how many fish does the shark eat over the course of 1 whole week?

Upper Elementary:

Question: A giant pacific octopus weighs 110 pounds. A blue-ringed octopus weighs 4 ounces. How many blue-ringed octopuses weigh the same amount as a giant pacific octopus?

 Middle School:

Question: An anemone catches 10 pounds of food over the course of a week and consumes 62.5% of it. A school of clownfish that lives with the anemones eat 3/8 of the anemone’s uneaten prey. What percentage of the anemone’s food goes uneaten?

Algebra and Up:

Question: Some species of pufferfish draw circles in the sandy seafloor to communicate. If a pufferfish draws a circle whose diameter is 12 times the length of the fish’s body, then how many times the length of the fish is the circumference of the circle? 

Challenge problem to take home. 20 points for the correct answer. 

In the following circle puzzle, dashed arrows denote addition while solid arrows denote multiplication.

If all the circles must contain positive integers, which number will replace the question mark?