Answer:
(A) 49
Explanation:
Given that the fractions are in their simplest form. So below the denominator cannot be a multiple of 3, 4, 5.
Breakdown:
Looking at option A (49), it is not a multiple of 3, 4, 5. So k can be 49.
Option B (50) is a multiple of 5. An even number like 4 so can be simplified.
Option C (51) is a multiple of 3 so can be simplified more. 3/51 = 1/17.
Option D (52) is an even number like 4 so can be simplified. 4/52 = 1/13.
Answer: x= -4,-5
Step-by-step explanation:
1. The combined volume of all the tanks at the aquarium is written in Scientific notation. Keeping this on mind, you can write it as following:

2. Now, you must sum the combined volume of all the tanks and the volume of the new tank to calculate the total volume of all of them:
3. Now, you can write the result in Scientific notation, as following:

The answer is: 
If this is greater than the first part of the number called by the spectator (i.e., ignoring the last two digits), then the last digit of your answer is the lower of the two possible values. Otherwise the last digit is the higher value. For example if the number called is 2809, the square root could be either 53 or 57.
Radius = diameter/2
35/2 = 17.5