Estimate the Speed of Recession of a Galaxy That Is $H = 20 \frac { \mathrm { km } / \mathrm { s } } { \mathrm { Mly } }$

Multiple Choice

Estimate the speed of recession of a galaxy that is 10 billion light-years away if $H = 20 \frac { \mathrm { km } / \mathrm { s } } { \mathrm { Mly } }$ ? $\left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$

A) $0.5 \mathrm { c }$
B) $0.3 \mathrm { c }$
C) $0.7 \mathrm { c }$
D) $0.1 \mathrm { c }$