2024 AMC 8 Problems/Problem 12
Revision as of 13:27, 26 January 2024 by Kittymath2021 (talk | contribs)
Problem
Rohan keeps a total of 90 guppies in 4 fish tanks.
- There is 1 more guppy in the 2nd tank than in the 1st tank.
- There are 2 more guppies in the 3rd tank than in the 2nd tank.
- There are 3 more guppies in the 4th tank than in the 3rd tank.
How many guppies are in the 4th tank?
Solution 1
Let = the number of guppies in the first tank.
Then, we have the following for the number of guppies in the rest of the tanks:
- the number of guppies in the second tank
- the number of guppies in the third tank
- the number of guppies in the fourth tank
The number of guppies in all of the tanks combined is 90, so we can write the equation
.
Simplifying the equation gives
.
Solving the resulting equation gives , so the number of guppies in the fourth tank is .
The correct answer is .
- C. Ren, Thomas Grover Middle School