Caleb bought 10 cartons of ice cream and 4 cartons of frozen yoghurt. Each carton of ice cream cost $4 and each carton of frozen yoghurt cost $1. How much more did Caleb spend on ice cream than on frozen yoghurt? Give the rationale and then the answer.
Let's think step by step. The cost of the ice cream is 10 × $4 = $40. The cost of the frozen yoghurt is 4 × $1 = $4. Caleb spent $40 − $4 = $36 more on ice cream than on frozen yogurt.. The answer is: 36.

A plant supplier was able to sell 20 pieces of orchids for $50 each and 15 pieces potted Chinese money plant for $25. The money he earned was then used to pay his two workers $40 each and to buy new pots worth $150. How much money was left from the plant supplier's earnings? Give the rationale and then the answer.
Let's think step by step. The plant supplier earned $50 x 20 = $1000 for the orchids. He earned $25 x 15 = $375 for the potted Chinese money plants. So, his total earnings was $1000 + $375 = $1375. Then he paid $40 x 2 = $80 to his workers. He used a total of $80 + $150 = $230 for the worker's pay and new pots. Hence, he was left with $1375 - $230 = $1145 from his earnings.. The answer is: 1145.

It takes Dawn 2 hours to paint 1 watercolor painting. She was recently commissioned to paint a series of 12 paintings. Dawn will earn $3,600.00 for these 12 paintings. How much money does Dawn make per hour? Give the rationale and then the answer.
Let's think step by step. It takes her 2 hours to paint 1 picture and she needs to paint 12 pictures so it will take 2 * 12 = 24 hours. Dawn will make $3,6000.00 for 24 hours of work which means she makes 3600 / 24 = $150.00 per hour of work.. The answer is: 150.