Answer:
20kph
Step-by-step explanation:
10 * 2 = 20
Maybe a picture of what the assigment is can help me give you an answer?
its b !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
So, let planet X's orbital period be T and its mean distance from the sun be A. Also let planet Y's orbital period be T_1, so that means if planet Y's mean distance from the sun were double that of planet X:

Which means that the orbital period in planet Y is increased by a factor of 
We have

The rational root theorem suggests that other possible roots may be -6, 6, -3, 3, -2, 2, -1, and 1. It turns out that
is a root, since
, so
is also a factor and we have

Finally, we can factorize the remaining quotient easily:

so the other factors are
,
, and
.