Random Puzzles 

Workings

Hint
A baker's dozen is 13.

Answer
Hours in a week.

Reasoning
A dozen is usually 12, but a baker's dozen is usually 13.

So a dozen (12) baker's dozen (13) = 12 x 13 = 156.

There are 24 hours in a day, and 7 days in a week.

So there are 24 x 7 hours in a week = 168.

Workings

Hint
How many walls can be built in 20 days?

Answer
4 days.

Reasoning
In 20 days, Sam can build 1 wall, and Taylor and Kelly can each build 2 walls.

So, in 20 days, 5 walls can be built.

Therefore, one wall will take 4 days to build.

Workings

Hint
A very common sequence.

Answer
Violet.

From the colours of the rainbow.

Workings

Hint
Try starting with the cube root of the number.

Answer
195 x 197 x 199.

Reasoning
Since we're after three numbers that multiply together, a good place to start is the cube root of 7,644,585, which is roughly 196.99.

Let's try dividing by the closest odd number to 196.99:

   7644585 ÷ 197 = 38805

We're now after whole divisors of 38,805, so trying either odd number either side of 197 might work.

Trying either 195 or 199 gives the answer.

Double-Checking
   195 x 197 x 199 = 7,644,585

Note
Trying the closest odd number to the cube root always works, and the other two numbers are the odd numbers either side.