Robert, a sales agent, earns a basic salary of $1250 per month and, 10% commission on his monthly sales. Last month, his total sales were $23600. He allocated 20% of his total earnings to savings and the rest of the money to his monthly expenses. How much were his monthly expenses last month?
Let's think: Robert earned a commission of $23600 x 10 / 100 = $2360. So, he earned a total of $1250 + $2360 = $3610. And, he saved $3610 x 20 / 100 = $722. Therefore, his total expenses last month was $3610 - $722 = $2888.. The answer is: 2888.

Hanna has twice as many erasers as Rachel. Rachel has three less than one-half as many erasers as Tanya has red erasers. If Tanya has 20 erasers, and half of them are red, how many erasers does Hanna have?
Let's think: Half of Tanya's 20 erasers are red, so she has 20 / 2 = 10 red erasers. One - half as many erasers as Tanya has red erasers is 10 / 2 = 5 red erasers. Rachel's three less than one - half as many erasers as Tanya's red erasers, which is 5 - 3 = 2 erasers. Hanna has twice as many erasers as Rachel, for a total of 2 * 2 = 4 erasers.. The answer is: 4.

Once a week, it takes Kitty 5 minutes to pick up toys and straighten the living room. It takes another 20 minutes to vacuum the living room floor, seating and drapes. She spends 15 minutes cleaning the windows and 10 minutes dusting the furniture. After 4 weeks, how long has Kitty spent cleaning just the living room?
Let's think: 5 minutes for picking up toys, 20 minutes to vacuum, 15 minutes on windows and 10 minutes on furniture is 5 + 20 + 15 + 10 = 50 minutes. After 4 weeks, she has spent 4 weeks * 50 minutes / week = 200 minutes cleaning the living room.. The answer is: 200.

Nancy, the librarian, is shelving books from the cart. She shelved 12 history books, 8 romance books, and 4 poetry books from the top section of the cart. Half the books on the bottom section of the cart were mystery books, which she quickly put back into place. Then, she shelved the remaining books from the bottom of the cart, including 5 Western novels and 6 biographies. How many books did she have on the book cart when she started?
Let's think:
Half of the books on the bottom section of the cart are mystery books, which means they are the same as the number of Western novels and biographies put together. So there are 5 + 6 = 11 mystery novels. Add them all together, and there are 12 history + 8 romance + 4 poetry + 11 mystery + 5 Western + 6 biographies = 46 books total.. The answer is: 46.