Dont know an equation for the problem in the description.

Question

A geologists collected 13 rocks that have exactly the same weight. If 9 of these rocks with an additional 5 ounce weight at one end of the balance scale the remaining rocks in a 23-ounce weight at the other end of the scale what is the number of ounces in the weight of these rocks?

Answer 1

Total number of rocks = 13 

Let each one be X ounce 

 

 Given 9X + 5 = 4 X+23 For balancing two side 

 

5X = 23 - 5 = 18

 

So each rock = 3.6 Ounces

 Wt of 13 rocks = 3.6*13 = 46.8 Ounces