Track / Stage 1 / 113 of 240 #113 of 2444

Problem 113

Combinatorics Difficulty 1.3 Find the answer CEMC Pascal · Canada · 2020

Matilda counted the birds that visited her bird feeder yesterday. She summarized the data in the bar graph shown.

The percentage of birds that were goldfinches is

$15\%$
$20\%$
$30\%$
$45\%$
$60\%$

Your answer

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Official solutions — 2

From the bar graph, Matilda saw 6 goldfinches, 9 sparrows, and 5 grackles.

In total, she saw $6 + 9 + 5 = 20$ birds.

This means that the percentage of birds that were goldfinches is $\dfrac{6}{20} \times 100\% = \dfrac{3}{10} \times 100\% = 30\%$ .

From the bar graph, Matilda saw 6 goldfinches, 9 sparrows, and 5 grackles.

In total, she saw $6 + 9 + 5 = 20$ birds.

This means that the percentage of birds that were goldfinches is $\dfrac{6}{20} \times 100\% = \dfrac{3}{10} \times 100\% = 30\%$ .

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty, ordering) added by this project.