The given table shows the number of clerical and officer cadre employees recruited by four different banks A, B, C and D from 2011 to 2014. Year → A Officer | A Clerk | B Officer | B Clerk | C Officer | C Clerk | D Officer | D Clerk 2011 — 260 | 458 | 255 | 460 | 205 | 428 | 265 | 470 2012 — 310 | 569 | 286 | 584 | 230 | 539 | 246 | 554 2013 — 350 | 730 | 321 | 725 | 340 | 740 | 361 | 725 2014 — 400 | 890 | 452 | 845 | 380 | 850 | 482 | 860 Compute the ratio of the number of officer cadre employees of bank A to the number of officer cadre employees of bank C.

Correct — A. The whole item is one image: a table of clerical and officer cadre recruitment by four banks A, B, C and D from 2011 to 2014, then the demand for the ratio of bank A's officers to bank C's officers. Only the two Officer columns matter.

Bank A officers: 260 + 310 + 350 + 400 = 1320
Bank C officers: 205 + 230 + 340 + 380 = 1155
1320 : 1155, divide both by 15 → 88 : 77, then by 11 → 8 : 7 → option (a)

Why the others are wrong

• (b)
  5 : 6 — 5 : 6 — this is below 1, but bank A took more officers than bank C in every one of the four years, so the ratio asked for has to exceed 1.
• (c)
  7 : 8 — 7 : 8 — the reciprocal of the answer, which is C to A. The stem names bank A first, and order is the whole content of a ratio.
• (d)
  6 : 5 — 6 : 5 — this needs bank C's officers to total 1,100. The column adds to 1,155, and 1320 : 1155 is 8 : 7, not 6 : 5.

A table question rewards column discipline before arithmetic. The stem names two quantities only — officer cadre of bank A, officer cadre of bank C — and every clerk figure on the page exists to be ignored.

Take the ratio of the sums, not the sum of the ratios. Add each column once, then divide once. Working year by year and averaging the four ratios gives a different number, and a wrong one.

Reduce with the factors you can see: 1320 and 1155 are both divisible by 15, and the resulting 88 : 77 by 11.

Key facts

• Bank A's officer recruitment over 2011 to 2014 totals 1,320.
• Bank C's officer recruitment over the same four years totals 1,155.
• 1320 : 1155 reduces to 8 : 7, both terms sharing a factor of 165.

Common traps

• Adding the Clerk column by mistake, since it sits immediately beside Officer under one bank name
• Writing the ratio as C : A because C is read further along the row
• Averaging the four yearly ratios instead of dividing the two column totals

No directly related past PYQ was found.