Question 792848
Upstream: d=(r)(t1)

Downstream: d=(4r)(t2)

(r)(t1)=(4r)(t2)

t1=(4)(t2)

t2=22-t1

t1=(4)(22-t1)

t1=88-(4)(t1)

(5)(t1)=88

t1=88/5 min (Answer)