I think some of the answer keys are wrong, please confirm.

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45. In a consumer survey, 85% of those surveyed liked at least one of three products: 1, 2, and 3. 50% of those asked liked product 1, 30% liked product 2, and 20% liked product 3. If 5% of the people in the survey liked all three of the products, what percentage of the survey participants liked more than one of the three products?

A) 5

B) 10

C) 15

D) 20

E) 25
Soln: n(1U2U3) = n(1) + n(2) + n(3) - n(1n2) - n(2n3) - n(1n3) + n (1n2n3)
85=50+30+20- [n(1n2) - n(2n3) - n(1n3)] +5
[n(1n2) - n(2n3) - n(1n3)] = 20

The solution says it's 20, but I recall the answer from another test that I took previously that says it should be 10. This is how it's done: I draw three circles, and call 1 repeats X, Y and X, the 2 repeat =N

50+30+20 - (X + Y + Z) -2N = 85
100-(X+Y+Z) -10=85, X+Y+Z = 5

X+Y+Z+N=5+5 = 10.




51. How many integers from 0 to 50, inclusive, have a remainder of 1 when divided by 3?

A.14 B.15. C.16 D.17 E.18

Soln: if we arrange this in AP, we get
4+7+10+.......+49

so 4+(n-1)3=49: n=16
C is my pick


The answer states that it's C. 16, but does the calculation consider 0 also? Because 0 divided by 3 also has a remainder of 1 doesn't it? So the answer should be D. 17 right???
Source: — Problem Solving |

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by Gabby1 » Wed Sep 19, 2007 11:42 pm
Sorry for 51 I meant to say the solution fails to consider 1, because 1 divided by 3 also has a remainder of 1. Sorry for the confusion.