At first, Pierre, Oliver and Owen had the same amount of money. After Owen spent some of his money, Pierre spent ²₇ of his money and Oliver spent ¹₂ of his money, Pierre had $42 more than Oliver. In the end, the total amount of money the three boys had left was $258. How much money did Owen spend?

	Pierre	Oliver	Owen	Total
Before	7x2 =  14 u	2x7 = 14 u	14 u
Change	- 2x2 = - 4 u	- 1x7 = - 7 u	- ?
After	5x2 = 10 u	1x7 = 7 u		$258

The amount that Pierre and Oliver each had at first is the same.  Make the amount that they each had the same.  LCM of 7 and 2 is 14.

Amount that Pierre had more than Oliver in the end
= 10 u - 7 u
= 3 u

3 u = 42

1 u = 42 ÷ 3 = 14

Amount that Pierre and Oliver had in the end
= 10 u + 7 u
= 17 u
= 17 x 14
= $238

Amount that Owen had in the end
= 258 - 238
= $20

Amount that Owen had at first
= 14 u
= 14 x 14
= $196

Amount that Owen spent
= 196 - 20
= $176

Answer(s): $176