Question

Difficulty: HardSorting and Multi-Column Ordering

The table below displays operational metrics for eight semiconductor fabrication facilities (fabs).

Fab IDRegionWafer Yield Rate (%)Defect Density (defects/cm²)Monthly Capacity (k Wafers)Operating Cost per Wafer ($)
Fab AlphaAsia-Pacific94.20.08120450
Fab BetaNorth America91.50.1285520
Fab GammaEurope95.80.0560490
Fab DeltaAsia-Pacific91.50.10140410
Fab EpsilonEurope93.00.0995475
Fab ZetaNorth America94.20.07110510
Fab EtaAsia-Pacific89.80.15150390
Fab ThetaEurope95.80.0670465

Evaluate the following statement as True or False:

If the table is sorted primarily by Wafer Yield Rate (%) in descending order, and secondarily by Defect Density (defects/cm²) in ascending order to break ties, the facility ranked 4th has a lower Monthly Capacity than the facility ranked 3rd.

Answer: Answer

Answer

The statement is False.
Sorting primarily by Wafer Yield Rate (%) descending places facilities with 95.8%95.8\% yield in positions 1–2 and facilities with 94.2%94.2\% yield in positions 3–4. To break the tie for positions 3 and 4, we sort Defect Density in ascending order. Fab Zeta (0.070.07 defects/cm²) precedes Fab Alpha (0.080.08 defects/cm²). Thus, Fab Zeta is ranked 3rd with a capacity of 110110 k wafers, and Fab Alpha is ranked 4th with a capacity of 120120 k wafers. Since 120120 is greater than 110110, the statement claiming the 4th-ranked facility has a lower capacity is False.

Step-by-Step Solution

1
Identify the primary sorting criterion and group facilities by Wafer Yield Rate (%) in descending order.
Group 1 (95.8%95.8\%): Fab Gamma, Fab Theta
Group 2 (94.2%94.2\%): Fab Alpha, Fab Zeta
Group 3 (93.0%93.0\%): Fab Epsilon
Group 4 (91.5%91.5\%): Fab Beta, Fab Delta
Group 5 (89.8%89.8\%): Fab Eta
Primary sort requires ordering by highest Wafer Yield Rate first.
2
Apply the secondary sorting criterion (Defect Density in ascending order) to break ties in the top groups to determine ranks 1 through 4.
For Group 1 (95.8%95.8\%):
- Fab Gamma (0.050.05) ranks 1st
- Fab Theta (0.060.06) ranks 2nd

For Group 2 (94.2%94.2\%):
- Fab Zeta (0.070.07) ranks 3rd
- Fab Alpha (0.080.08) ranks 4th
Ascending order means lower numerical defect density comes first.
3
Compare the Monthly Capacity values of the 3rd and 4th ranked facilities.
- 3rd Ranked (Fab Zeta): 110110 k Wafers
- 4th Ranked (Fab Alpha): 120120 k Wafers
Since 120>110120 > 110, the 4th-ranked facility has a higher capacity than the 3rd-ranked facility.
Verifies whether the condition '4th-ranked facility has a lower Monthly Capacity than 3rd-ranked facility' holds true.

Key Concept

Multi-Column Sorting and Secondary Tie-Breaking Logic
Rate this question