Bonny just bought her 13th pair of shoes, which is 5 less than twice as many pairs of shoes as Becky owns. Bobby has 3 times as many pairs of shoes as Becky has. How many shoes does Bobby have? Give the rationale and then the answer.
Let's think step by step. Let x be the number of pairs of shoes that Becky owns. Since 13 pairs is 5 less than twice as many pairs as Becky owns, then the relationship is 2x - 5 = 13. Adding 5 to each side of the equation, we get 2x = 18. Solving for x, we get x = 9. Since Bobby has 3 times as many pairs of shoes as Becky has, then Becky has 3 * 9 = 27 pairs of shoes.. The answer is: 27.

Betty is planning to host her friends over for a party. She buys drinks, cakes, and ice creams at a unit cost of $2, $10, and $5 respectively. How much does she spend if she buys 10 drinks, 5 cakes, and 100 ice creams? Give the rationale and then the answer.
Let's think step by step. The amount she spends on buying drinks is $2 * 10 = $20. The amount she spends on buying cakes is $10 * 5 = $50. The amount she spends on buying ice creams is $5 * 100 = $500. The total amount she spends is $20 + $50 + $500 = $570.. The answer is: 570.

Mason is mixing up some salad dressing. He takes a bowl that holds 150 ml and fills it 2/3rds with oil and 1/3rd with vinegar. The oil weighs 5 g/ml and the vinegar weighs 4 g/ml. How many grams does the salad dressing weigh? Give the rationale and then the answer.
Let's think step by step. First find how many ml of oil Mason adds by multiplying the volume of the bowl by the proportion filled with oil: 150 ml * 2 / 3 = 100 ml. Then repeat the process to find how many ml of vinegar he added: 150 ml * 1 / 3 = 50 ml. Now find the weight of the oil by multiplying the volume by the weight / volume ratio: 100 ml * 5 g / ml = 500 g. Do the same procedure with the weight and weight / volume ratio of the vinegar to find its weight: 50 ml * 4 g / ml = 200 g. Now add the weight of the oil and the vinegar to find the weight of the salad dressing: 500 g + 200 g = 700 g.. The answer is: 700.