Answer: 5 branches and 16 birds.
Step-by-step explanation:
If the number of birds is B, and the number of branches is N.
First we have the equation:
B = 3*N + 1
(3 birds per branch + 1 that was flying around)
for the second equation we have:
B = 4*(N - 1)
(4 birds per branch, but one branch had no birds on it, so there are N -1 branches used)
now we can write:
3*N + 1 = 4*(N - 1)
3*N + 1 = 4*N - 4
4 + 1 = 4*N - 3*N
5 = N
So we had 5 branches, now we can replace it in one of the equations and find the number of birds.
B = 3*N + 1 = 3*5 + 1 = 16
