Why is 6 afraid of 7?

A large water tank has two inlet pipes (a large one and a small one) and one outlet pipe. It takes 3 hours to fill the tank with the large inlet pipe. On the other hand, it takes 6 hours to fill the tank with the small inlet pipe. The outlet pipe allows the full tank to be emptied in 9 hours.

What fraction of the tank (initially empty) will be filled in 0.64 hours if all three pipes are in operation? Give your answer to two decimal places (e.g., 0.25, 0.5, or 0.75).

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

A small town is visited by an ice-cream truck every day. On the first day of February, the truck visits as usual and 5 children, one from each of the first 5 houses on the street buys an ice cream that is of the different flavor from each other along with a completely different topping.

Go through the details below and find out which child lives in which house and bought which ice-cream flavor with which topping:

1. Jim lives between the child who bought the Raspberry topping and the child who bought mango ice cream.

2. Joyce, whose house has an even number, bought the cherry topping. Nancy does not live next to Joyce.

3. The blackcurrant ice cream had no topping.

4. The child who lives in house number 2 had the butterscotch ice cream. The child in house number 3 did not have chocolate ice cream.

5. Mike had banana ice cream. He hates banana cherry.

6. The child who had the cashew topping lives in house number 5. Dustin does not live in house number 4.

Please note that the odd numbered houses and the even numbered houses are located on the exactly opposite sides of the street.

A game is being played where eight players can last for thirty-five minutes. Six substitutes alternate with each player in this game. Thus, all players are on the pitch for the same amount of time including the substitutes.

For how long is each player on the pitch?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

What does this below rebus puzzle mean?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?