Let the number be N and (50 - N)
Then, 1/N + 1/(50-N) = 1/12

Correct Option: A

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

Correct Option: B

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

Let the number be N.
Then (N/2)² - N = 48

Correct Option: A

Let the number be N.
Then (N/2)² - N = 48
⇒ N²/4 - N = 48
⇒N² - 4N-192= 0
⇒ (N-16) (N+12) = 0
⇒ N = 16
∴ The square root of the number is 4.

Let the three consecutive numbers be x, x+1 and x+2 respectively
∴ Diff between first and third numbers = (x + 2) - x

Correct Option: D

Let the three consecutive numbers be x, x+1 and x+2 respectively
∴ Diff between first and third numbers = (x + 2) - x
= 2

Let the number be N.
Then, N - N/3 = 48

Correct Option: D

Let the number be N.
Then, N - N/3 = 48
2N/3 = 48.