Answer: 1. 63; 2. 84; 3. 104 4. 1:2
Step-by-step explanation: Since Zoey has $28, and the ratio is 4:5, we can multiply the ratio by 7 on both sides so that it is 28:35, giving $35 for andrew, and this $28+$35=$63. Since the ratio of red to white marbles has a sum of 10, but there are 120, we multiply the ratio by 120/10=12, to make the ratio applicable to the scenario, so 7 times 12 = 84 red marbles. Same way for the theater question, 195/15=13, so 8 times 13= 104, and so 104 people are boys. For the last question you can simply divide both sides by 5 (or think of it as a fraction, 5/10=1/2).