2015 AMC 10A Problem 4

Below is the professionally curated solution for Problem 4 of the 2015 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2015 AMC 10A solutions, or check the answer key.

All of the real AMC 8, AMC 10, AMC 12, and AIME problems in our complete solution collection are used with official legal permission of the Mathematical Association of America (MAA).

Concepts:ratio and proportionfraction

Difficulty rating: 1020

4.

Pablo, Sofia, and Mia got some candy eggs at a party. Pablo had three times as many eggs as Sofia, and Sofia had twice as many eggs as Mia. Pablo decides to give some of his eggs to Sofia and Mia so that all three will have the same number of eggs. What fraction of his eggs should Pablo give to Sofia?

112\dfrac{1}{12}

16\dfrac{1}{6}

14\dfrac{1}{4}

13\dfrac{1}{3}

12\dfrac{1}{2}

Solution:

Let mm be the number of candy eggs that Mia had. Then SofiaSofia had 2m2m eggs and PabloPablo had 6m6m eggs.

The total number of eggs is then m+2m+6m=9m. m + 2m + 6m = 9m. For all of them to have the same number of eggs, they each must have 9m÷3=3m9m \div 3 = 3m eggs.

Sofia needs 3m2m=m3m - 2m = m more eggs. This means Pablo must give m6m=16\dfrac{m}{6m} = \dfrac{1}{6} of his eggs to Sofia.

Thus, B is the correct answer.

Problem 4 in Other Years