tlong bantu jawab ya..mksih

U1 = 2km = 13 ribu
U2 = 4km = 19 ribu
=> 22 km = U22
a = 13
b = 6
Un   = a + ( n - 1 ) b
U11 = 13 + ( 11 - 1 ) 6
U11 = 13 + ( 10 ) 6
U11 = 13 + 60
U11 = 73 ribu (B)