The neutron is uncharged. That's why it was
given a name built on "neu" from "neutral".
Answer:
f = 5 cm
Explanation:
using the thin lens equation, given as follows:

where,
f = focal length = ?
do = the distance of object from lens = 20 cm
di = the distance of image from lens = 6.6667 cm
Therefore,

<u>f = 5 cm</u>
<span>Planet A orbits faster than Planet B, i believe is the answer. hope that helps
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