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        riddles >> easy >> IQ Test Math Problems
        
(Message started by: Vincent_469 on Jul 6^th, 2003, 1:22pm)

Title: IQ Test Math Problems
Post by Vincent_469 on Jul 6^th, 2003, 1:22pm

Hiyas....I had trouble with this math problems on a IQ test and I wanted to know how to solve it...there are 3...read carefully, explain it to me and then answer.

-A boy is 4 years old and his sister is 3x as old as he is. When the boy is 12 years old, how old will his sister be?

A) 16
B)20
C)24
D) 28
E) 32

Sue is both the 50th best and the 50th worst student at her school. How many students attend her school?

A)50
B) 75
C)99
D)100
E) 101

2 cars start off at the same point on a straight highway facing opposite directions. Each car drives for 6 miles, takes a left turn and drives for 8 miles. How far apart are the 2 cars?

A) 2
B)11
C)14
D)20
E)26

Please help me...and yet thank you!!! ^_^

// 2:01 AM 9/1/2003 William Wu: thread moved to easy section; title changed to be more descriptive

Title: Re: Math problem that need thinking....
Post by Icarus on Jul 6^th, 2003, 2:19pm

(1) When the boy is 4, his sister is 3x4 = 12 years old. The boy is 12 eight years later. His sister's age 8 years later is 12+8 = 20. So the answer is B. (The relation that his sister is 3x older than him only holds when he is 4 and she is 12).

(2) If Sue is 50th best student, then there are 49 students better than her. If she is 50th worst, there are 49 students worse than her. So the total number of students is (49 worse) + (1 Sue) + (49 better) = 99 students. The answer is C.

(3) the drive path looks like this:


.............|
.............|
.............|
.............|
.............|
.............|
.............|
.............|
 ------------
|
|
|
|
|
|
|
|

where the starting point is in the middle of the horizontal line.

The diagonal from the two end positions is the distance between the two cars at the end. The endpoints differ by 12 miles horizontally, and 16 miles vertically. The length (d) of the diagonal is found using the Pythagorean formula:

d² = 12² + 16² = 144 + 256 = 400 = 20²

so d=20 and the answer is D.

Title: Re: Math problem that need thinking....
Post by Vincent_469 on Jul 17^th, 2003, 12:29am

OHHHHHHHH! I get it now! Thank you SO SO SO much!!!! thanks alot!!! ;D