参考答案:

　　1.Correct Answer: 107

　　Explanation:

　　Second term = 3x3 + 2 = 11; Third term = 3x11 +2 = 35; Fourth term = 3x35 +2 = 107

　　2.Correct Answer: 8

　　Explanation:

　　If the average of 3 and x = 5, the total = 10, and x = 10-3 = 7

　　If the average of 5 and y = 7, the total = 14, and y = 14-5 = 9

　　The average of x and y is 7+9 / 2 = 8

　　3.Correct Answer: 9

　　Explanation:

　　The volume of a cylinder = area of base x height

　　6π = circumference = 2πr ; 6/2 = r

　　Area of base = πr² = π 3x 3 = 9π

　　81π = 9π x height; height = 9

　　4.Correct Answer: 8262

　　Explanation:

　　The largest number is 9521

　　The smallest is 1259

　　The difference = 8262

　　5.Correct Answer: 19

　　Explanation:

　　The numbers containing 8 are:

　　8, 18, 28, 38, 48, 58, 68, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 98

　　6.Correct Answer: 15

　　Explanation:

　　To find a perfect square we need the prime factors.

　　60 = 2 x 2 x 3 x 5

　　To turn it into a perfect square we need to multiply by 3 x 5 = 15

　　(So that the prime factors are in groups of two = 2 x 2 x 3 x 3 x 5 x 5)

　　7.Correct Answer: 410

　　Explanation:

　　By drawing three lines inside the figure (from angle y to angles 110, 110 and 90) we can divide the figure into four triangles. Therefore the sum of the interior angles = 4 x 180 = 720

　　x + y + z = 720 - 110 - 110 - 90 = 410

　　8.Correct Answer: 7500

　　Explanation:

　　She has 50 choices of action books which ca be combined with any of 15 romances. This give us 50 x 15 =750 combinations which in turn can be combined with any of 10 historical novels to give a total number of choices 750 x 10 = 7500

　　9.Correct Answer: 40

　　Explanation:

　　Decreasing x by 25 per cent gives 0.75x

　　Increasing y by 25 percent gives 1.25y

　　The new fraction is 0.75x/1.25y = 0.6x/y

　　This is 0.4 less (= 40 percent)

　　10.Correct Answer: 1/60

　　Explanation:

　　Total number of tracks is 60. If one is chosen at random the probability is 1/60. This is very easy; don’t be distracted by irrelevant information.