[Question]: Julie wants to give her favorite cousin a $2345 mountain bike for his birthday. So far, she has saved $1500. Since the birthday is still a few weeks away, Julie has time to save even more. She plans on mowing 20 lawns, delivering 600 newspapers, and walking 24 of her neighbors' dogs. She is paid $20 for each lawn, 40 cents per newspaper, and $15 per dog. After purchasing the bike, how much money will Julie have left?
[Answer]: Mowing lawns will earn Julie 20 * 20 = 400 dollars. Her earnings, in dollars, from delivering newspapers will be 600 * 40 / 100 = 240 dollars. After walking 24 of her neighbor's dogs, she will earn 24 * 15 = 360 dollars. She will therefore earn a total of 400 + 240 + 360 = 1000 dollars. Combining earnings from her job with her savings will give Julie 1000 + 1500 = 2500 dollars. Subtracting the cost of the mountain bike from the total will leave Julie with a balance of 2500 - 2345 = 155 dollars.
So the answer is 155.

[Question]: A school bought pencils and pens. A pencil costs $2.50, while a pen costs $3.50. How much do 38 pencils and 56 pens cost?
[Answer]: The 38 pencils cost $2.5 x 38 = $95. The 56 pens cost $3.5 x 56 = $196. The total cost of 36 pencils and 56 pens is $95 + $196 = $291.
So the answer is 291.

[Question]: A group of 300 athletes spent Saturday night at Ultimate Fitness Camp. The next morning, for 4 hours straight, they left the camp at a rate of 28 athletes per hour. Over the next 7 hours, a new group of athletes trickled into the camp at a rate of 15 athletes per hour. Immediately thereafter, the camp gate was shut and everyone went to bed. What is the difference in the total number of athletes in the camp over the two nights?
[Answer]:
The number that left the camp on Saturday morning was 4 * 28 = 112 athletes. This means that in the camp there remained 300 - 112 = 188 athletes. The new group trickling in on Sunday morning comprised 7 * 15 = 105 athletes. The number that slept at the camp on Sunday night is therefore 188 + 105 = 293 athletes. Since there were 300 athletes on Saturday night, the difference is 300 - 293 = 7 athletes.
So the answer is 7.