Jack and Jill leave home together for a pool one mile away. Jill cycles at a constant 10 miles/hour and Jack walks at a constant 4 miles/hour. How many minutes earlier does Jill arrive?
A mathematics contest has 10 questions. Each correct answer earns 1 point, and wrong or blank answers lose no points. What is the least number of contestants needed to ensure that four have the same score?
On Halloween, Hannah’s candies are stolen. Her four guests say:
- Cupcake: “Chocolate stole them.”
- Chocolate: “Jelly stole them.”
- Gummy: “I did not steal them.”
- Jelly: “Chocolate is lying.”
A fish tank has base dimensions 60 cm by 30 cm and water depth 24 cm. Then 60% of a rock of volume $600\ \mathrm{cm}^3$ is submerged in the water. Find the new water depth.