Question: The ratio of boys to girls in a family is 5:7. The total number of children in the family is 180. If the boys are given $3900 to share, how much money does each boy receive?
Answer with step-by-step thinking: The total ratio representing the number of children in the family is 5 + 7 = 12. From the total ratio of children in the family, 5 / 12 represent the number of boys, meaning that the number of boys in the family is 5 / 12 * 180 = 75. If the boys are given $3900 to share, each boy receives $3900 / 75 = $52.
So the answer is 52.


Question: Omi is twice as old as Kimiko. Arlette is 3/4 times as old as Kimiko. If Kimiko is 28 years old, calculate the average age of the three?
Answer with step-by-step thinking: If Kimiko is 28, Omi is 2 * 28 years = 56 years old. Arlette is 3 / 4 * 28 years = 21 years old. If you add up their ages, it sums to 21 years + 56 years + 28 years = 105 years. The average age for the three is 105 years / 3 people = 35 years / person.
So the answer is 35.


Question: Ruby is taking dance lessons. They cost $75 for 10 classes in one pack. She can add additional classes at the price of 1/3 more than the average price of a class on the lesson in the pack. if she takes 13 total classes, how much does she pay?
Answer with step-by-step thinking:
The classes in the pack cost $7.5 each because 75 / 10 = 7.5. An additional class costs $10 because 7.5 x (1 + (1 / 3)) = 10. She buys 3 extra classes because 13 - 10 = 3. Her three additional classes cost $30 because 3 x 10 = 30. Her total cost is $105 because 75 + 30 = 105.
So the answer is 105.