Driver License

[Abdulla]

To receive a driver license, sixteen year-olds at Culliver High School have to pass both a written and a practical driving test. Everyone has to take the tests, and no one failed both tests. If 30% of the 16 year-olds who passed the written test did not pass the practical, how many sixteen year-olds at Culliver High School received their driver license?

(1) There are 188 sixteen year-olds at Culliver High School.

(2) 20% of the sixteen year-olds who passed the practical test failed the written test.


OA is C

[vishubn]

TO GET licence !! pne has to pas both !!

stem states --- 30 percent 16's written --pass pract-fail
70 percent might be have passed both--- but we dont know how many pass pract and failed written

A)total number of stduents--188 but nothing with the second choice
Insuff

B)we know out of 70percent--- where practical -passed.... in that 20 percent failed written


using both

total =188

30%--- written test pass and practical fail

57 people written pass but practial fail
131 people have passed practical ... in which 20 percent failed thats is 27 ---- written

188-57-27=104

104 got licence ( rounded off)


Tree diagram should yeild the answer...

OA C

vishu

[ronniecoleman]

To receive a driver license, sixteen year-olds at Culliver High School have to pass both a written and a practical driving test. Everyone has to take
the tests, and no one failed both tests. If 30% of the 16 year-olds who passed the written test did not pass the practical,
how many sixteen year-olds at Culliver High School received their driver license?

(1) There are 188 sixteen year-olds at Culliver High School.

(2) 20% of the sixteen year-olds who passed the practical test failed the written test.

x = who passed written
y = who passed pratical

given:

x + y = 188

now also given

70/100 x = 80/100 y ( no for recieved licenses are equal.)

solve for x and y


IMO C

But the values are not integers...so probably the test makers have to plug in some different values....

[cramya]

My bad Abdulla! I meant to post the book details elsewhere(under a different post).

[Abdulla]

Unfortunately, they're in front of me right now.. they're in my hand, my heart, my mind, and my eyes. but still struggling

[umaa]

Answer C.

Explanation:

Total: 188
30% of the 16 year-olds who passed the written test did not pass the practical.

ie, 188 * (30/100) = 56


20% of the sixteen year-olds who passed the practical test failed the written test.

188 * (20/100) = 38.

Students who got the license: 188 - 56 - 38 = 94

[crisro]

There is a major flaw with this question; it says that everybody has to take the test but it doesn't say how many of them have taken the test. It might be that there are still students that they haven't taken the test yet.
The answer should be E and not C.

[SmartAssJun]

Answer C.

Explanation:

Total: 188
30% of the 16 year-olds who passed the written test did not pass the practical.

ie, 188 * (30/100) = 56


20% of the sixteen year-olds who passed the practical test failed the written test.

188 * (20/100) = 38.




Students who got the license: 188 - 56 - 38 = 94

I'm sorry but I think you miss something in the question though the answer is C.
Since those who passed each of the tests don't represent the total of the 188.
We should handle this more accurately, first let's have X and Y, in which X is
the population of the people who passed the written test and Y is those who passed
the practial. And we know that 70%(100%-30%) of the people who passed the written
test also passed the practial, and 80%(100%-20%) of those who passed the practial
test also passed the other. This two are basically the same thing. So we can get
the equation that 7X=8Y. And then we replace Y with X
So we get X+7/8X-0.7X =188, hence X=160 Y=140
So 112 16-year-olds got the liscence.