Maths Olympiad Prep

Library / /5 of 57

, 2009

Algebra Difficulty 1.0 Junior Prove it Canada

Alex counts the number of students in her class with each hair colour, and summarizes the results in the following table:

Hair Colour: Blonde, Number of Students: 8
Hair Colour: Brown, Number of Students: 7
Hair Colour: Red, Number of Students: 3
Hair Colour: Black, Number of Students: 2

(a) What percentage of students in the class have blonde hair?

(b) What percentage of students in the class have red or black hair?

(c) How many students in the class with blonde hair would have to dye their hair black for the percentage of students in the class with black hair to be 20%20\%?

(d) How many students with red hair would have to join the class so the percentage of students in the class with red hair is equal to 32%32\%?

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