Chapter 12 Sequences and Series - 12.2 Analyze Arithmetic Sequences and Series - 12.2 Exercises - Problem Solving - Page 808: 67

$100$

Let $x$ be the amount given away by the committee on the first day. Then, on the subsequent days, we have $x+(x+50)+(x+100)+(x+150)+(x+200)=1000$ The total sum of these 5 prize amounts is: $5x+500=1000$ This gives: $x=100$