Data Sufficiency (DS) | Re: How many minutes would it take Guy to complete 15X2 phone calls at a c

It is clear that Ans is either C or E
Statement 1: X minutes to complete 1 phone call, this implies 1 min 1/x phone calls.
Further, 1/x phone calls in 1 min then 15X^2 in 15X^3 min (Not Suff.)
Statement 2: Every minute, guy completes X phone calls
X phone calls in 1 min, this implies 15X^2 in 15X min (Not suff.)

Combining 1 & 2,
X min to make 1 phone call (Statement 1), this implies 1 min to make 1/X phone calls
And from statement 2, 1 min = X calls
Equating 1 & 2 1/x=x implies x=-1(not
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