Paul can fill a pit in 4 hours. Renny can fill the same pit in 6 hours. If both work together, how many minutes will it take them to fill the pit? Assume each keeps a constant working rate and their work adds together.
Brian takes a day off from work every 4th day, and David every 5th day. They both have today off, and their next shared day off is a Monday. What day is today?
Tom can paint a classroom in 12 hours. Jerry can paint the same classroom in 4 hours. If they work together, each at their own constant rate, how many hours will they take to paint this classroom?
The largest four-digit number $A$ is formed using all the digits 4, 5, 0 and 3. The smallest four-digit number $B$ is formed using all those digits. Find $A-B$. Use each digit exactly once in each number.
At a function, the valet charged 10 dollars for a motorbike and 25 dollars for a car. There were 150 vehicles and 360 tires in total. How much did the valet earn from cars only? Count two tires per motorbike and four per car, with no spare tires included.
Enter the number of dollars, without a currency symbol or units.
In the pattern $15,17,21,A,35,45,B,\ldots$, what is $A+B$? Use the intended rule that the successive increases are consecutive positive even numbers, starting with 2.
A dancer is allowed to step on only one of the following tiles: 1 blue, 1 green, 2 red, 2 orange and 3 grey. The grey tiles are sticky and make the dancer stop dancing. If the chance of getting stuck on the very first step is $m/n$, find $m+n$.
**Assumptions for this self-study exercise:** Each of the nine tiles is equally likely to be chosen, and $m/n$ is written in lowest terms with positive whole-number numerator and denominator. The original question does not state these conditions.