2018 AMC 10B Problems/Problem 4
Problem
A three-dimensional rectangular box with dimensions , , and has faces whose surface areas are , , , , , and square units. What is + + ?
Solution 1
Let be the length of the shortest dimension and be the length of the longest dimension. Thus, , , and . Divide the first to equations to get . Then, multiply by the last equation to get , giving . Following, and .
The final answer is .
Solution 2
Simply use guess and check to find that the dimensions are by by . Therefore, the answer is .