Q14 of 52 Page 1

How many three-digit numbers are divisible by 12?

108, 120, 132, …, 996


a = 108,


d = 120 – 108 = 12


an = 996


a+(n – 1)d = an


Therefore,


108+(n – 1)12 = 996


(n-1)(12) = 996 – 108 = 888


(n – 1) = 888/12 = 74


n = 74+1 = 75


∴ There are 75 terms which are divisible by 12.


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