[Question]Ken had fifty pencils, and he wanted to share some of them with his two friends, Manny and Nilo. Ken gave ten pencils to Manny and ten more pencils to Nilo than he gave to Manny. He kept the rest of the pencils. How many pencils did Ken keep?
[Answer]Nilo received 10 + 10 = 20. Thus, Ken gave a total of 10 + 20 = 30. Therefore, Ken kept 50 - 30 = 20 pencils. The answer is 20.

[Question]The central Texas countryside contains many toads that come out at night. For every green toad, there are 25 brown toads, and one-quarter of the brown toads are spotted. If there are 50 spotted brown toads per acre, how many green toads are there per acre?
[Answer]If there are 50 spotted brown toads per acre, and this represents one - quarter of the brown toads, then there are 50 * 4 = 200 brown toads per acre. If for every 25 brown toads there is one green toad, then there are 200 / 25 = 8 green toads per acre. The answer is 8.

[Question]Kurt's old refrigerator cost $0.85 a day in electricity. He recently bought a new energy-efficient refrigerator that only cost $0.45 a day in electricity. How much money does Kurt save in a 30-day month with his new refrigerator?
[Answer]The old refrigerator costs $0.85 a day so for 30 days it costs .85 * 30 = $25.50. The new refrigerator costs $0.45 a day so for 30 days it costs .45 * 30 = $13.50. Over 30 days, Kurt saves 25.50 - 13.50 = $12.00 a month with his new refrigerator. The answer is 12.

[Question]Denver uses 7 pieces of wood for each birdhouse and he pays $1.50 for each piece of wood. If he makes a $5.50 profit per birdhouse, how much will Denver charge to Danny for buying two birdhouses?
[Answer]
The cost for making one birdhouse is $1.50 x 7 = $10.50. So the selling price of one birdhouse is $10.50 + $5.50 = $16. Thus, Denver will charge Danny $16 x 2 = $32 for the two birdhouses. The answer is 32.