I have teeth but i don't bite. Who Am I ?

What am I?

Can you find out the total number of triangles in the given figure?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

I have branches, but no fruit, trunk or leaves. What am I?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

There is something which you can be arrested for attempting but not for successfully completing.

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?