That's false.
Here's a counter-example:
If an animal is a dog, then it has four legs. This is true.
but
If an animal has four legs, then it is a dog. This is not necessarily true.
Another one:
If a shape is a square, then it has four sides. Always true.
but
If a shape has four sides, then it is a square. Usually not true.
Answer:
20,000
Explanation:
Mass of the saturn = 5.683 × 10^26
Mass of the mercury = 3.285 × 10^23
Now divide them
(5.683 × 10^26)/3.285×10^23
= 18.668.655
so approximately
it is 20,000 times greater than mercury.
Is there a missing sign? Because adding 5y to each side would make this 8 = 20 which is not possible