berapakah banyak suku pada barisan bilangan 3,10,17,24,....,80?

Barisan Aritmatika

3, 10, 17, 24, ... , 80
a = 3
b = U2 - U1 = 10 - 3 = 7

n = 1 + [(Un - a)/b]
n = 1 + [(80 - 3)/7]
n = 1 + [77/7]
n = 1 + 11
n = 12

Banyak suku pd barisan tsb = 12