Math Word Problems Quiz - DIFFICULT

You roll two fair 6-sided dice. What is the probability of rolling a 7? Give your answer as a percentage to 1 decimal place.

There is a task that needs to be done. If Tim does it alone, it will take him 24 days. If John does it alone, it will take him 30 days. If the two people do it together, how many days will it take? Give your answer to 3 significant figures.

Find the smallest number of people you need to pick such that two of these people are guaranteed to have the same birthday.

How many different permutations can be produced by rearranging the letters in the word JETPUNK?

A bag contains 3 red balls and 5 black balls. I take out one of the balls at random, and then take out a second ball without replacing the first. What is the probability that the second ball is red? Give your answer as a percentage.

On Saturday morning, Tom went to his friend's house by bike. He departed at 8 a.m. sharp and traveled the first 3 miles at an average speed of 10 miles per hour. Then, his bicycle broke and repairing it took him half an hour. He continued his journey at an average speed of 8 miles per hour and covered another 2 miles before arriving. At what time did Tom arrive at his friend's house?

The half-life of a radioactive particle is 5000 years. A sample of this particle is found to have 15% of its original energy remaining. What is the age of this sample? Give your answer to the nearest year.

A poker hand consisting of five cards is drawn at random from a standard 52-card deck. What is the probability that the hand contains NO face cards? Give your answer as a percentage to 1 decimal place.

Burning one gallon of gas produces 8.8 kilograms of carbon dioxide. I drove from Los Angeles to San Diego with an average consumption of 24 miles per gallon. Given that the two cities are 110 miles apart, how much carbon dioxide did I emit from the road trip? Give your answer in kilograms to 3 significant figures.

In the city of Oakfield, monthly electricity bills are charged as follows: (1) $0.30 per kilowatt-hour under 200 kWh, and (2) $0.50 per kilowatt-hour in excess of 200 kWh. Given that Jane's family, living in this city, consumed 270 kWh of electricity last month, how much did they pay for their electricity usage?