I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

The Federal bank of London is abducted by the robbers. The head of the robbers asked the cashier to empty their money vault to them and when suddenly cashier got a call from her father. To avoid any suspicion, the robber asked the cashier to pick the call and reply her father in the shortest manner possible.

The cashier told her father "Is there an emergency father, Call me when you are free and I will help you in your furnishing" and then the cashier hung up the phone.

After 10 minutes, police arrived at the crime scene.

How did the police know about the robbery?

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

Joseph organises an exotic office New year party at the beach to his important fellow employees.

Following are the important people that will come to the party

1. Joseph

2. Joseph 2 girlfriends- Carol Vanstone and Tracey Hughes

3. The sales head Clay Vanstone.

4. Clay Vanstone 2 associates.

5. Mr. Jeremy and his Secret Tab.

They all need to cross a small river to reach the beach, however, Joseph has got just one boat.

There are few rules for crossing the river.

1. The capacity of the boat is limited to just two people.

2. Clay Vanstone associates will not stay with Joseph without Clay Vanstone.

3. Carol Vanstone and Tracey Hughes will not stay with the Clay Vanstone without Joseph.

4. Mr. Jeremy would never leave the Secret Tab alone.

5. Secret Tab counts as a person.

6. Only Joseph, Clay Vanstone or Mr. Jeremy can drive the boat.

7. The two girlfriends Carol Vanstone and Tracey Hughes will not stay with the Clay Vanstone without Joseph.

8. No Associates would stay with Joseph without their Clay Vanstone.

9. Mr.Jeremy will not leave the Secret Tab alone.

The more you take me, the more you leave me behind.
Who Am I?

What word is represented by this rebus?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.