A flock of birds was flying around a tree. When they landed, three birds to a branch, no branches were left and one bird had to keep flying around the tree. Then, all the birds took off, flew around the tree again and landed to sit, four to a branch. Now, no birds were left flying but one branch had no birds sitting on it. How many branches were on the tree and how many birds were in the flock?

Question

Mathematics

Jade Kemp

2 November, 22:49

A flock of birds was flying around a tree. When they landed, three birds to a branch, no branches were left and one bird had to keep flying around the tree. Then, all the birds took off, flew around the tree again and landed to sit, four to a branch. Now, no birds were left flying but one branch had no birds sitting on it. How many branches were on the tree and how many birds were in the flock?

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Answers (1)

Know the Answer?

Kai Walls · Answer 1

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