Amy wrote 320 pages (rounded to nearest tens) in 20 days (rounded to nearest tens). On average, the...

[BTGmoderatorLU]

Source: e-GMAT

Amy wrote 320 pages (rounded to nearest tens) in 20 days (rounded to nearest tens). On average, the number of pages ‘x’ that Amy wrote per day must have been between -

A. \( 315/25 \le x \le 325/15\)
B. \(315/15 < x < 325/25\)
C. \(315/24 \le x \le 324/15\)
D. \(320/25 < x < 320/15\)
E. \(315/20 < x < 325/20\)

The OA is C

[Scott@TargetTestPrep]

Source: e-GMAT

Amy wrote 320 pages (rounded to nearest tens) in 20 days (rounded to nearest tens). On average, the number of pages ‘x’ that Amy wrote per day must have been between -

A. \( 315/25 \le x \le 325/15\)
B. \(315/15 < x < 325/25\)
C. \(315/24 \le x \le 324/15\)
D. \(320/25 < x < 320/15\)
E. \(315/20 < x < 325/20\)

The OA is C

Let p = the actual number of pages Amy wrote and let d = the actual number of days she wrote these pages. Then, we have 315 ≤ p ≤ 324 and 15 ≤ d ≤ 24. Since x = p/d, the maximum value of x is the maximum value of p divided by the minimum value of d, which is 324/15. Similarly, the minimum value of x is the minimum value of p divided by the maximum value of d, which is 315/24. That is, 315/24 ≤ x ≤ 324/15.

Answer: C