Table – Units Sold of 3 Products Product | Jan | Feb | Mar A | 100 | 120 | 110 B | 90 | 85 | 95 C | 150 | 160 | 155 Q: Which product had the highest average units sold?

Correct — D. For each product, add the three months and divide by 3.

A: (100 + 120 + 110) ÷ 3 = 330 ÷ 3 = 110
B: (90 + 85 + 95) ÷ 3 = 270 ÷ 3 = 90
C: (150 + 160 + 155) ÷ 3 = 465 ÷ 3 = 155

Compare: 155 > 110 > 90, so the highest average is C → option (d)

Why the others are wrong

• (a)
  A & C both — A averages 110 and C averages 155, so the two do not tie. An answer naming both would need their averages to be equal.
• (b)
  B — B has the lowest average, 90. All of B's months (90, 85, 95) sit below A's lowest month, 100.
• (c)
  A — A's 110 comes second. C's lowest month, 150, is already above A's highest, 120, so C must average more.

When every row covers the same number of periods, the highest average belongs to the highest total. Dividing each total by 3 cannot change the order.

Here you need not even add. C's smallest month (150) is larger than A's largest (120), and B stays below 100 throughout, so C wins on sight. When the rows overlap, compare the totals instead.

Key facts

• Average = sum of the values ÷ number of values.
• With equal counts, ranking by average and ranking by total give the same order.
• The totals here are A 330, B 270 and C 465.

Common traps

• Picking the row with the single highest month: here both point to C, but a row with one spike can have the lower average.
• Treating an option that names two products as a safe hedge: it is right only if their averages tie exactly.

No directly related past PYQ was found.