Given 5 (3/7)
First convert the given mixed fraction into improper fraction we get (38/7)
Let x be the number added to (38/7) to get 12
Therefore x + (38/7) = 12
x = 12 – (38/7)
By taking LCM for 7 and 1 is 7
x = (12 × 7 – 38)/7
x = (84 – 38)/7
x = (46/7)
Hence (46/7) is the number which is added to 5 (3/7) to get 12.