What number must be added to numerator and denominator of 3/4 to give 11/12?

Let the number be N.
Then, 3N/4 - 2N/3 = 5
? (9N - 8N) / 12 = 5
? N = 60

Let the number be N,
Then 4N/5 = 64
? N = 64 x 5/4 = 80
? Half of the number = 80/2 = 40

Let the other number be x.
Then, 10 + x = 2(x - 10)
? x = 30

Let the number be a and b.
Then, a² + b² = 80
and (a - b)²= 36
? a² + b² - 2ab = 36
? 2ab = (a² + b²)-36
= 80 - 36= 44
? Product = ab = 22

Let the number be a and b .
Then, (a+b)² = a² + b² + 2ab
= 289 + 2 x 120
= 289 + 240
= 529
? a+b = ?529 = 23

Let the number be 4N, 5N and 6N
Then, 4N + 5N + 6N/3 = 25
or 15N = 75
or N = 5
Then largest number = 6N = 6 x 5 = 30

Let the requirement odd integers be N, N +2 and N + 4
Then, N + (N + 2) + (N + 4) = 57
? 3N = 51
? N = 17
? The integers are 17, 19, 21.

Let the required number be N,
Then, N/6 = N - 40
? N + 240 = 6N
? N = 48.

Let the number be N and (50 - N)
Then, 1/N + 1/(50-N) = 1/12
? (50 - N + N) / {N(50 - N)} = 1/12
? N² - 50N + 600 = 0
? N = 30 or 20
? the number are 20, 30

Let the antecedent be N.
Then, N/24 = 2/3
? N = (24 x 2) / 3
= 16