Can you decipher the following common phrase?

T M C
A U O
H S M
W T E

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

A frog is at the bottom of a 30-meter well. Each day he summons enough energy for one 3-meter leap up the well. Exhausted, he then hangs there for the rest of the day. At night, while he is asleep, he slips 2 meters backwards. How many days does it take him to escape from the well?

They are three errirs in this question. Can you find them?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'