2 Questions From Kaplan QR - there's no right answer?

[organichemistry]

Jane's age is 1 1/2 times David's age. In 15 years Jane's age will be twice David's age. How old was Jane 8 years ago?
A) 30
B) 48
C) 67
D) 75
E) 83

The thing flat out doesn't work. I swear I know how to do algebra and it doesn't work.


Same thing for the next one... there's no right answer

What percent of a^3+b^2 is 3a+b if a=8 and b=4
A) 20%
B) 35%
C) 40%
D) 50%
E) 65%

a^3+b^2 would be 528
3a + b would be 28

So what percent of 528 is 28? like 5.3%, and i don't see that.

---

Members don't see this ad.

 

[organichemistry]

bump... anyone got a clue?

 

[boon]

.

 

[tinman831]

she would have been 37

 

[organichemistry]

she would have been 37

the question sucks to begin with because it doesn't specify if jane's age 15 years from now will be twice david's age 15 years from now... or twice david's age now.

but yeah... she would have been 37 if you compare it to david's age now. if you compare it to david's age 15 years from now... it doesn't work at all.

 

[SMC2UCLA2_]

the question sucks to begin with because it doesn't specify if jane's age 15 years from now will be twice david's age 15 years from now... or twice david's age now.

but yeah... she would have been 37 if you compare it to david's age now. if you compare it to david's age 15 years from now... it doesn't work at all.

In general when you see this wording, you are supposed to add X years (15 here) to both peoples' ages. I cant get an answer for this question and Im assuming the second one is just as bad but i havent tried it.

 

[786mine]

What percent of a^3+b^2 is 3a+b if a=8 and b=4
A) 20%
B) 35%
C) 40%
D) 50%
E) 65%

a^3+b^2 would be 528
3a + b would be 28

So what percent of 528 is 28? like 5.3%, and i don't see that.

5.3% is correct. Remember this term = "is" on top, "of" on bottom. Hence,

Percentage = (is/of)x100