Final answer:
To find the percent of breadcrumbs used, divide the number of breadcrumbs used by the total number of breadcrumbs and multiply by 100. In this case, they used 100% of their breadcrumbs.
Step-by-step explanation:
To find the percent of breadcrumbs that Mr. and Mrs. Doyle used, we need to divide the number of breadcrumbs used by the total number of breadcrumbs they had saved up, and then multiply by 100.
In this case, they used 30 breadcrumbs out of their original savings of 30 breadcrumbs. So the calculation would be:
(30 / 30) * 100 = 100%
Therefore, they used 100% of their breadcrumbs.