Q: Heather helps her neighbour pick weeds out of her garden. She gets paid 5 cents for every weed she picks. On average, how many seconds can she take to pick a weed if she wants to earn $10 an hour?
A: In an hour, she needs to earn $10 * 100 cents / $1 = 1000 cents. In an hour, she must pick 1000 cents / 5 cents = 200 weeds. There are 1hr * (60 minutes / 1 hr) = 60 minutes in an hour. There are 60 minutes * (60 seconds / 1 minute) = 3600 seconds in an hour. She has 3600 seconds / 200 = 18 seconds to pick each weed. The answer is 18.

Q: Susan has 21 cats and Bob has 3 cats. If Susan gives Robert 4 of her cats, how many more cats does Susan have than Bob?
A: After giving away four of her cats, Susan has 21 - 4 = 17. Susan has 17 - 3 = 14 more cats than Bob. The answer is 14.

Q: Lara is a contestant on a fun game show where she needs to navigate an inflated bouncy house obstacle course. First she needs to carry a backpack full of treasure through the obstacle course and set it down on the other side, which she does in 7 minutes and 23 seconds. Second, she needs to crank open the door to the obstacle course so she can go back through, which takes her 73 seconds. After she gets through the door she traverses the obstacle course again and makes it out faster without the backpack, in 5 minutes and 58 seconds. How many seconds total does it take her to complete the obstacle course?
A:
It takes Lara 7 minutes and 23 seconds to make it through the obstacle course the first time. 7 minutes x 60 seconds per minute = 420 seconds + 23 seconds = 443 seconds to get through the first part of the obstacle course. The second stage of the obstacle course she completes in 73 seconds + 443 seconds = 516 seconds. It takes 5 minutes and 58 seconds for Lara to get through the obstacle course the second time. 5 minutes x 60 seconds per minute = 300 + 58 seconds = 358 seconds. Combined, it takes Lara 516 + 358 seconds = 874 seconds for Lara to run the whole obstacle course. The answer is 874.