Let the length of the blue paper roll be B cm.
Then, the length of the red paper roll is 2B cm.
The number of equal parts of length 9 cm that Kira cuts the blue paper into is B/9.
So, the number of star shapes she draws is 3*(B/9) = B/3.
The number of equal parts of length 7 cm that Kira cuts the red paper into is (2B)/7 = 2B/7.
So, the number of heart shapes she draws is 5*(2B/7) = 10B/7.
Thus, the fraction of shapes Kira drew that were star shapes is (B/3)/(B/3 + 10B/7).
This simplifies to (B/3)/(7B/21 + 30B/21) = (B/3)/(37B/21) = B/3 * 21/37B = 21/3*37 = <<21/3*37=7/37>>7/37.
Therefore, the fraction of shapes Kira drew that were star shapes is 7/37. Answer: \boxed{\frac{7}{37}}.
Kira had a roll of blue paper and a roll of red paper. The length of the roll of blue paper is 1/2 the length of the roll of red paper. She cut the roll of blue paper into equal parts of length 9 cm and on each part she drew 3 star shapes. After that, she cut the roll of red paper into equal parts of length 7 cm and on each part she drew 5 heart shapes. What fraction of the shapes Kira drew were star shapes?
1 answer
2 answers