This is a timed quiz. You will be given 60 seconds per question. Are you ready?
Since f(a) = 4a − 3 and f(a) = 9, then 4a − 3 = 9 so that 4a = 12 and a = 3. Similarly, f(b) = 4b−3 = 5 so that 4b = 8 and b = 2. Finally, f(a+b) = f(3+2) = f(5) = 4 · 5 − 3 = 17.
The least possible score in one game will occur when the player has scored the maximum possible (52 points) in each of the other two games. These two games add to 104 points, leaving 141 − 104 = 37 points as the lowest possible score for the remaining game.
The largest negative integer is −1, and the smallest positive integer is 1, so the sum is 4(−1) + 1 = −4 + 1 = −3.
Since 0.6666 = 2/3, and any fraction with integers on the top and bottom is a rational number, answer A is correct. Why are the other answers incorrect? The number 2/3 can be correctly gridded as “.666” or “.667” or “2/3” but not as “0.66”. Also, 67/100 = 0.67 is not the same as 0.6666. Finally, 0.6666 isn’t a little devil every night of the week, so we can’t be sure about last night.
Strategy: work with the answers. Use the answers to try choices for the number of green marshmallows. If there are 9 green marshmallows (answer C), then there are 6 + 9 = 15 total marshmallows, so the probability of choosing a purple one is 6/15 = 2/5 > 1/3, so answer C is incorrect. We need more green marshmallows to get a lower probability for choosing a purple marshmallow, so we try an answer to the right. If there are 12 green marshmallows (answer D), then there are 6 + 12 = 18 total marshmallows, so the probability of choosing a purple one is 6/18 = 1/3. Answer D is correct. Math Teacher Solution: Let x be the number of green marshmallows. Then, 6 + x is the total number of marshmallows. The probability of choosing a purple marshmallow is the number of purple marshmallows (6) divided by the total number of marshmallows (6 + x). So, we need: 6/6+x=1/3 Cross-multiplying, 18 = 6 + x so that x = 12.
Strategy: work with the answers. Go through the answers, substituting each for x and using it in the problem until it works. For example, to check x = 4 (answer B), subtract 4 from 36 to get 32, and divide by 4, resulting in 8, so answer B is incorrect. You will find that only answer D gives you the final result of 2. Math Teacher Solution: Convert the words into an equation for x: 36 − x x = 2. Multiplying both sides by x gives 36 − x = 2x so that x = 12.
Strategy: work with the answers. Suppose the answer is C so that the largest of the three consecutive integers is 10. Then, the group of integers must be 8, 9, and 10. Four times the smallest is 32, and three times the largest is 30, so answer C is incorrect. If we use answer D, our group of integers is 10, 11, and 12, but 40 6= 36, so answer D is incorrect as well. Since answer C was closer, try going the other way and work with answer B. Here, the group is 6, 7, and 8, and 4×6 = 3×8, so answer B is the correct answer. Math Teacher Solution: Let x be the smallest of the three integers. Then, x+1 is the next integer, and x+2 is the biggest integer. We need 4x = 3(x+2), so that 4x = 3x + 6, resulting in x = 6.
First, determine the new price of the shoes: 40% of $40 is (40/100) · $40 = $16, so the new price of the shoes is $40 − $16 = $24. At this point, we can work with the answers to figure out which one is correct: increase each answer by 20% until we get $24. The correct answer is B since 20% of $20 is $4 and $20 + $4 = $24.
