How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

There are three boxes. One is labeled "APPLES" another is labeled "ORANGES". The last one is labeled "APPLES AND ORANGES". You know that each is labeled incorrectly. You may ask me to pick one fruit from one box which you choose.

How can you label the boxes correctly?

John is a strange liar.

He lies on six days of the week, but on the seventh day, he always tells the truth.

He made the following statements on three successive days:

Day 1: "I lie on Monday and Tuesday."
Day 2: "Today, it"s Thursday, Saturday, or Sunday."
Day 3: "I lie on Wednesday and Friday."

On which day does John tell the truth?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Solve the equation in the image by looking at the pattern closely.

Find the missing number in the series below

13 -21 34 -55 ? -144

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

What breaks yet never falls, and what falls yet never breaks?

I am a number I am not an odd number I am higher than 90 I am not higher than 100 If you subtract me from 100, you get nothing. What number am I?