If FROG - PARK = 10, MAID - LITE = 1, then HARM –

Solution

The logic followed here is: The absolute difference between the place value of the 1st letter of the 1st word and the 2nd word, as per the English alphabetical series.

'FROG – PARK → Place value of the 1st letter (F) in 'FROG' = 6 . Place value of the 1st letter (P) in 'PARK' = 16. Code = |6 - 16| = 10. 'MAID - LITE' → Place value of the 1st letter (M) in 'MAID' = 13. Place value of the 1st letter (L) in 'LITE' = 12. Code = |13 - 12| = 1.

'HARM - ROPE'→ Place value of the 1st letter (H) in 'HARM' = 8. Place value of the 1st letter (R) in 'ROPE' = 18. Code = |18 - 8| = 10.