itsmek80 wrote:

A device calculates the worth of gem stones based on quality such that a gem with a quality rating of q - 1 is worth 5 times more than a gem with a quality rating of q. According to this device, the worth of a gem with a quality rating of p - r is how many times greater than that of a gem with a rating of p?

(A) \(p^5-r^5\)

(B) \(r^5\)

(C) \((p-r)^5\)

(D) \(5^{(p-r)}\)

(E) \(5r\)

please follow the rules..

q - 1 is worth 5 times more than a gem with a quality rating of q

the relation could be..

1) 5*1

2) 5^1

so for p-r. it can be

1) 5*r

2) 5^r

only 5r is there, so the answer is E

Otherwise

also substitute p as q and r as 1 and the ANSWER should be 5

lets see the choices

(A) \(p^5-r^5........q^5-1^5=q^5-1\)...NO

(B) \(r^5........1^5\).... NO

(C) \((p-r)^5.......(q-1)^5\)...NO

(D) \(5^{(p-r)}.....5^{q-1}\)...NO

(E) \(5r.....5*1=5\)....YES

E

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372

2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

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