Question

You and your friend collect each rocks and fossils. your friend collects three times as many rocks and half as many fossils as you. you collect 20 objects. your friend collects 20 objects. how many rocks andhow many fossils do you each collect. PLEASE ANSWER FAST! I DONT WANNA FAIL!!

Answer 1

• you - 4 rocks and 16 fossils
• friend - 12 rocks and 8 fossils

Explanation:

Let the rock be r and the fossil be f

Equations

• You: r + f = 20
• Friend: 3r + 1/2f = 20

Double the second equation and subtract the first one:

• 2(3r + 1/2f) - (r - f) = 2*20 - 20
• 6r - r = 20
• 5r = 20
• r = 4

Then find f:

• f = 20 - 4 = 16

So you collect 4 rocks and 16 fossils

Friend collects:

• 4*3 = 12 rocks and
• 1/2*16 = 8 fossils