A baseball bat and a ball cost \$1.10 in total. The bat costs \$1 more than the ball. How much does the ball cost?

The time is quarter past three. What is the angle between the hour and minute hands at 3:15?

A contractor is doing work for 7 days at your home. You have a gold bar that is worth \$7000. You need to pay him \$1000 every day and \$7000 in total. You have to pay him in gold by using the gold bar. How can you pay him \$1000 worth of gold everyday by cutting the gold bar only twice?

By cutting the gold bar twice, you can have 3 pieces of gold.

Let the gold bar pieces be GB1, GB2 and GB3. They are worth \$1000, \$2000 and \$4000 respectively.

Day1: Give GB1

Day2: Take GB1, Give GB2

Day3: Give GB1

Day4: Take GB1, GB2 and give GB3

Day5: Give GB1

Day6: Take GB1, Give GB2

Day7: Give GB1

Four people need to cross a rickety rope bridge to get back to their camp at night. Unfortunately, they only have one flashlight and it only has enough light left for seventeen minutes. The bridge is too dangerous to cross without a flashlight, and it’s only strong enough to support two people at any given time. Each of the campers walks at a different speed. One can cross the bridge in 1 minute, another in 2 minutes, the third in 5 minutes, and the fourth takes 10 minutes to cross.

How do the campers cross the bridge in 17 minutes?