Some bananas are packed into a box in stacks. Each stack has the same number of bananas in each row as the number of rows. The number of stacks is also the same as the number of rows. If there are 84 stacks of bananas in the box, what is the total number of bananas in the box?
Soobin drove 2 hours longer than Hyeonwoo at an average speed 4 kilometers per hour faster than Hyeonwoo. Yejoon drove 4 hours longer than Hyeonwoo at an average speed 8 kilometers per hour faster than Hyeonwoo. If Soobin drove 60 kilometers more than Hyeonwoo, then how many more kilometers did Yejoon drive than Hyeonwoo?
Yejoon can complete some work in 6 days, while Minsuh can complete the same work in 3 days. They started the work together, and when the work was half complete, Minsuh fell ill and Yejoon had to finish the remaining work. How long did it take to complete the work?
A water tank has two types of taps (type-A and type-B). A tap of type-A can fill the tank in 26 minutes, while a tap of type-B can fill the same tank in 39 minutes. If there are 3 type-A taps and 2 type-B taps that can be used to fill the tank, how long will it take to fill an empty tank?