9. Lengkapilah urutan bilangan berikut ini!
a. 18, 16, 15, 12, 13
b. 18, 16, 13, 15, 12
c. 18, 16, 15, 13, 12
d. 18, 15, 16, 13, 12
Jawaban: c. 18, 16, 15, 13, 12
10. Lengkapilah urutan bilangan di bawah ini!
18, …, 16, 15, …, 13, …, 11
a. 17, 12, 14