1.Correct Answer: D
Explanation:
0.127 expressed as a fraction = 127/1000
1/8 can also be expressed as (1 x 125) / (8 x 125) = 125/1000
The difference is 2/1000, which is 1/500
2.Correct Answer: D
Explanation:
Using Pythagoras theorem we can see that 122 + 152 is not equal to 182
(All the others obey the theorem a2 + b2 = c2)
3.Correct Answer: D
Explanation:
Area remaining is the area of the rectangle - 2 x area of a circle.
(16 x 8) - 2π r2
But r = 4; so area remaining is 128 - 101(approx) = 27 (approx)
4.Correct Answer: C
Explanation:
a2 - b2 can be expressed as (a + b)(a - b)
So the fraction can be written as (a + b)(a - b)/ (a + b)
Which is equal to (a - b)
5.Correct Answer: E
Explanation:
The best approach is to pick a number that satisfies the rules that x and y are greater than 0. So for example you could choose 25 for y.
The value of x before doubling is then 25 - 50/25 = 23
The value after doubling y will be 50 - 50/50 = 49, which is more than double.
6.Correct Answer: D
Explanation:
This could be tricky unless you realize that the absolute value signs lead to the conclusion that x = 4x – 3 and also –x = 4x – 3
If we solve these equations we get x = 1 and x = 3/5 = 0.6 and so since 1 is not an option, the answer is D.
(You could also have substituted the answer choices in the equation.)
7.Correct Answer: C
Explanation:
The hour hand moves from pointing to 12 to pointing to half way between 2 and 3. The angle covered between each hour marking on the clock is 360/12 = 30. Since the hand has covered 2.5 of these divisions the angle moved through is 75.
8.Correct Answer: B
Explanation:
Average speed = total distance / total time
Total distance covered = 6 miles; total time = 45 minutes = 0.75 hours
Average speed = 6/ 0.75 = 8 miles/hour
9.Correct Answer: E
Explanation:
Do not assume that a circle must have its origin where AB intersects the line l.
You could take any point on line l and use if as the center of a circle such that the distance from that point to either A or B is the radius.
10.Correct Answer: E
Explanation:
Total distance covered by the first wheel = d, which is the equivalent of 100 x circumference. Circumference = 2xπ
Circumference of the second wheel = 2yπ
Revolutions covered by the second wheel = 100(2xπ / 2yπ , which simplifies to 100x/y
最新热文推荐: