Answer:
Right answer is choice D.
a=-4
b=2
c=7
so therefore a*b*c=-4*2*7
A
Step-by-step explanation:
this is because an input can only have one output, but an output can have many input
let they meet after t hours
2.5t+3t=22
5.5 t=22
55/10 t=22
t=22×10/55=4 hours
after 4 hours they meet.
