Respuesta :

at 1 p.m. there were 16 seagulls....at 3 p.m. there were 40 seagulls....that means in 2 hrs (from 1 to 3) there was an increase of (40 - 16) = 24 birds....
24 birds in 2 hrs = 24/2 = 12 birds per hr....ur constant rate is 12 per hr