Nina made a two-layer cake and a dozen cupcakes for her friend’s birthday party. Each layer of cake takes the same amount of sugar to make as a dozen cupcakes. Nina used 720 grams of sugar to bake everything. How many grams of sugar are in one cupcake? Give the rationale and then the answer.
Let's think step by step. Nina made 2 cake layers which were equal to 2 x 12 = 24 cupcakes. She made the equivalent of 24 + 12 = 36 cupcakes in all. Thus, there are 720 / 36 = 20 grams of sugar in a cupcake.. The answer is: 20.

There are twice as many centipedes as humans on a certain island and half as many sheep as humans. How many sheep and humans in total are on the island if the number of centipedes is 100? Give the rationale and then the answer.
Let's think step by step. The number of humans on the island is 100 / 2 = 50. There are 1 / 2 * 50 = 25 sheep on the island. The total number of sheep and humans is 25 + 50 = 75.. The answer is: 75.

Oleg is an event organizer. He is organizing an event with 80 guests where 40 of them are men, half the number of men are women, and the rest are children. If he added 10 children to the guest list, how many children will there be at the event? Give the rationale and then the answer.
Let's think step by step. There are 40 / 2 = 20 women at the event. Hence, there are a total of 40 + 20 = 60 men and women at the event. So, the total number of children at the event is 80 - 60 = 20. After Oleg added 10 children to the guest list, there are a total of 20 + 10 = 30 children.. The answer is: 30.