The Cookie Zombie

Number Theory Level 3

Five zombie cookies appear in a kitchen. Every day, each zombie cookie infects one more, so that their number doubles every day. There is a limit to their growth: each zombie cookie must eat two grams of flour each day to survive. Write a formula that calculates the flour eaten from day 1 to day x.

When solving, make the formula yourself - do not merely look at each of the multiple answers.

day 1 day 2 day 3 day 4
5 cookies 10 cookies 20 cookies 40 cookies
10g consumed 20g 40g 80g
5 × 2 x 5\times 2^{x} 10 × 2 x − 5 10\times 2^x-5 5 × 2 x − 1 + 5 5\times 2^{x-1} + 5 10 × 2 x − 10 10 \times 2^{x} - 10

A Former Brilliant Member by A Former Brilliant Member

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

0 solutions

No explanations have been posted yet. Check back later!

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...