Question: Celia is creating a budget for the next 4 weeks. She wants to spend no more than $100 a week on food. For rent for her apartment, she plans to spend $1500. She has $30 set aside for video streaming services for the month. She also has $50 planned for one month of cell phone usage. After she adds up all of her spending for the month she wants to set aside 10% of it to put into savings. How much money is Celia going to put into her savings account?
Answer with step-by-step thinking: Celia has budgeted $100 a week for 4 weeks for food, $100 x 4 = $400 worth of food for the month. She has one monthly cost of $1500 for her rent + $30 for video streaming services + $50 for her cell phone = $1580 of single monthly costs. Celia wants to set aside 10% of the $400 + $1580 = $1980 for her savings account. 10% of her savings account is .10 x 1980 = $198 to add to her savings account.
So the answer is 198.

Question: Jenny decided to get a cat with her girlfriend. They agreed to split all the costs down the middle except for they would each buy their own toys for the cat. The adoption fee was $50, the vet visits cost $500 for the first year and the monthly cost of food was $25. She bought $200 in toys. How much did Jenny spend on the cat in the first year?
Answer with step-by-step thinking: The total cost for food was 25 * 12 = $300. So their shared expenses were 300 + 50 + 500 = $850. So Jenny spent 850 / 2 = $425 on shared expenses. So the total cost she paid was 425 + 200 = $625.
So the answer is 625.

Question: A party hall has 3 decorative light bulbs; a red light bulb which comes on every 2 seconds, a green one every 3 seconds and a blue one every 4 seconds. If they are put on at the same time, what is the shortest time after which the three bulbs will be on at the same time?
Answer with step-by-step thinking:
The blue light bulb comes on every 2 seconds so it will be on after 2, 4, 6, 8, 10, 12, 14... seconds (multiples of 2). The red light bulb comes on every 3 seconds so it will be on after 3, 6, 9, 12, 15, 18... seconds (multiples of 3). The blue light bulb comes on every 4 seconds so it will be on after 4, 8, 12, 16, 20... seconds (multiples of 4). The shortest time after which all three will be on is 12 seconds which is the least common multiple of the set of multiples.
So the answer is 12.