11. Correct answer: (B)
Given:
Z W Y X
Two adjacent may be interchanged
The entire sequence can be reversed
To find:
The least number of changes needed to put the letters into alphabetical order from left to right
Solution:
We need to change the sequence from Z W Y X to W X Y Z.
The least steps needed would involve changing from
Z W Y X to Z Y X W and then reverse the entire sequence.
Swap W and Y; Z W Y X → Z Y W X
Swap W and X; Z Y W X → Z Y X W
Reverse entire sequence: Z Y X W → W X Y Z
The least number of changes needed is 3.
Answer: (B) 3
12. Correct answer: (D)
Given:
A cube with edges of length 4 cm
A rectangular box 20 cm by 24 cm by 32 cm
To find:
The number of cubes needed to fill the rectangular box
Solution:
Volume of cube = 4 × 4 × 4 = 64
Volume of rectangular box = 20 × 24 × 32 = 15360
Divide volume of rectangular box by volume of cube
= 15360 ÷ 64 = 240
Note that you should only divide the volumes when you are sure that the smaller shape can fit into the larger shape without any leftover space.
Answer: (D) 240
13. Correct answer: (E)
Given:
0 < n < 1
To find:
Find the correct ordering of
Solution:
Answer: (E) n 2 < n < √n
14. Correct answer: (C)
Given:
The figure
To find:
Median of the slopes
Solution:
Topic(s): Coordinate geometry, statistics
Answer: (C)
15. Correct answer: (A)
Given:
When it is noon (EST) in New York City, it is 9.00 a.m. (PST) in San Francisco
A plane took off from New York City at noon EST and arrived in San Francisco at 4.00 p.m. on the same day
A second plane left San Francisco at noon PST and took exactly the same amount of time for the trip
To find:
The second plane’s arrival time (EST) in New York City
Solution:
When it is 9:00 a.m. PST, it is 12:00 noon EST.
The time difference from PST to EST is +3 hours.
A plane took off at 12:00 noon EST and arrived at 4:00 p.m. PST.
4:00 p.m. PST would be 4 + 3 = 7:00 p.m. EST.
The time taken would be from 12:00 noon to 7:00 p.m., which is 7 hours.
A second plane took off at 12:00 noon PST and took the same amount of time as the first plane, which is 7 hours. It would then be arriving at 7:00 p.m. PST.
7:00 p.m. PST would be 7 + 3 = 10.00 p.m. EST
Answer: (A) 10.00 p.m. EST
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