Bonnie withdrew $1,200 from her savings account. She spent 1/5 of the money on travel arrangements. She spent 2/3 of the remaining amount at the hardware store. Finally, she treated her friend to lunch with some of the remaining money. After lunch, Bonnie had $300.50 left. How much money did Bonnie spend on lunch? Bonnie spent $ __ on lunch.

 1/5 of the money on travel arrangements :
 $1200/ 5 = $240

so $1200 - $240 = $960
2/3 of the remaining amount at the hardware store:
$960/3 x 2 = $640

remaining money: $960 - $640 = $320

after lunch Bonnie had $300.50 left
$320 - 300.50 = $19.50

Bonnie spent on lunch: $19.50