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

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

What time is it when an elephant sits on a fence?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

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

Can you find out the remainder when 3^300 is divided by 5?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

What number should come in place of the question mark below?

I am Huge on Sunday and Saturday.
I am small from Tuesday to Thursday.
I do not exist on Monday and Friday.
Who am I?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.