How many such pairs of letters are there in the word SINGAPORE each of which…
2024
How many such pairs of letters are there in the word SINGAPORE each of which has as many letters between them in the word as in the English alphabets?
- A.
One
- B.
Two
- C.
Three
- D.
More than three
Attempted by 4 students.
Show answer & explanation
Correct answer: D
Concept
In a "letter-pair" puzzle a pair of letters qualifies when the number of letters lying BETWEEN them in the given word equals the number of letters lying between them in the English alphabet. The alphabetical gap is measured WITHOUT regard to direction — a pair counts whether the two letters run forward (A to Z) or backward through the alphabet. So for every pair compare two gaps, gap-in-word and gap-in-alphabet, and keep the pair only when the two are equal.
Application
Number the letters of SINGAPORE by position and note each letter's alphabet rank:
Position | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
|---|---|---|---|---|---|---|---|---|---|
Letter | S | I | N | G | A | P | O | R | E |
Alphabet rank | 19 | 9 | 14 | 7 | 1 | 16 | 15 | 18 | 5 |
Scan every pair and keep only those whose gap-in-word equals gap-in-alphabet (gap = count of letters strictly between):
Pair | Letters between in word | Letters between in alphabet | Keep? |
|---|---|---|---|
I and G | 1 (N) | 1 (H) | Yes |
A and E | 3 (P, O, R) | 3 (B, C, D) | Yes |
P and O | 0 (adjacent) | 0 (O, P adjacent) | Yes |
P and R | 1 (O) | 1 (Q) | Yes |
Four distinct pairs satisfy the rule, so the total number of qualifying pairs is more than three.
Cross-check
Re-test each kept pair independently with the equal-gap rule, and confirm no other pair (for example S and I, N and G, O and R, R and E) meets it — each of those has unequal word and alphabet gaps. The four valid pairs all hold, so the count is more than three.