I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

You have to put a letter on the following to make it a meaningful word. The only challenge is that you can't use 'E'.

S E Q U E N C _

A Car driver was heading down a street in Washington. He went right past a stop sign without stopping, he turned left where there was a 'no left turn' sign and he went the wrong way on a one-way street. Then he went on the right side of the road past a cop car. Still, he didn't break any traffic laws. Why not?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

How many words can a pen with half refill write?

Find the next number in the series below

21 32 54 87 131 ?

What occurs twice in a week, once in a year but never in a day?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C