The number of values of 'a' such that the nine digit number 8544a5894 is divisible by 7 is
A) 1 B) 2 C) 3 D) 7

Ok, how on earth are you supposed to figure this out?

Question

The number of values of 'a' such that the nine digit number 8544a5894 is divisible by 7 is
A) 1 B) 2 C) 3 D) 7

Ok, how on earth are you supposed to figure this out?

steve816 · Answer

My guess is that the best way to do this is just trial and error using the numbers 0 through 9?

sillybilly123 · Answer

You're probably supposed to be learning modular arithmetic, calculators not allowed !

Zarkon · Answer

https://en.wikipedia.org/wiki/Divisibility_rule#Divisibility_by_7

Vijeya3 · Answer

Yeah @steve816 I think that would be hit and trial method.
Because, honestly, that is the least time-consuming method, as compared to some original method for this, (which I have never heard of yet)

ldenault · Answer

i agree with steve

Allison · Answer

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