He is going to hike 8*=40 hours
That means he will be hiking for 40*2.5=<<40*2.5=100>>100 miles
So he needs 100*.5=<<100*.5=50>>50 pounds of supplies
With the resupply he can get up to 1+.25=<<1+.25=1.25>>1.25 times his initial pack
That means his initial pack has to weigh 50/1.25=<<50/1.25=40>>40 pounds
#### 40