2019 · Q104
When the digits of two-digit numbers are reversed, the number increases by 27, the sum of such two-digit numbers
general-mental-abilityquantitative-aptitude
- A235
- B249
- C213
- D180
Explanation
Reversal increases the number by 27 = 9 x 3, so the digits differ by 3. The valid two-digit numbers are 14, 25, 36, 47, 58 and 69, whose sum is 249. Hence B. The stored key D has been corrected per UPSC's official answer key.