A maths symbol is hidden in the below Bar Graph. Can you decipher it?

Riddle me this, Riddle me that,
What am I? I am made of wood, but you can't see me down?

If eleven plus two equals one, what does nine plus five equal?

The UN Security Council has how many member states?

a) 15
b) 10
c) 20
d) 25

Can you find the mistake in the below statement?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

John was born on March 5, 1970, in Delhi, India. Jacob was born 25 days before John. The year when they took birth, Republic Day fell on Monday.

Can you find out on what day was Jacob born?

Find the next number in the series below

21 32 54 87 131 ?

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?

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 _