Since they are splitting the money that he has which is $24 into eighths we will divide 24 by 8 and see what each eighth is equal to. 24 divided by 8 is 3. So each eighth is worth $3. Now to find how much 5 eighths equal to we take $3, the amount for one eighth, and multiply it by 5, the amount of eighths Joaquin spent. 3 multiplied by 5 is 15. So Joaquin spent $15 on his pair of jeans.