Maths Olympiad Prep

Library / /261 of 387

, 2024

Algebra Difficulty 2.2 Junior Find the answer Canada

Last year, Lloyd ate cookies in the percentages shown in the pie
chart.

Figure 0

The number of gingerbread cookies that he ate was two times the
number of sugar cookies that he ate. What percentage of the cookies that
he ate were gingerbread cookies?

Pick one

Solution

The percentage of cookies that Lloyd ate that were chocolate chip
or oatmeal was 33%+22%33\% + 22\% which equals 55%55\%. This leaves 100%55%=45%100\% - 55\% = 45\% of the cookies that were gingerbread or sugar. Since Lloyd ate two times as many gingerbread cookies as sugar cookies, then 23\frac{2}{3} of the 45%45\%, or 30%30\%, were gingerbread cookies.

Figure for this problem

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

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