If set Q consists of all three digit numbers divisible by 4, what is

Question

If set Q consists of all three digit numbers divisible by 4, what is the mean of the set?

(A) 498
(B) 499.5
(C) 548
(D) 549.5
(E) 550

CareerGeek · Accepted Answer

The 3 digit numbers which are multiples of 4 are 100, 104, 108, . . . . . . . 996
The above series is in AP.

Formula:
If a series is in AP, Mean = Median =  \frac{(First term + Last term)}{2}

So, Mean =  \frac{(First term + Last term)}{2} 
=  \frac{(100 + 996)}{2} 
=  \frac{1096}{2} 
= 548

IMO Option C

Pls Hit Kudos if you like the solution

Lampard42 · Answer

The set will be in a AP with starting term 100 and last term = 996.

Last term = 996 = 100+(n-1)4 solving for n we get 225.

Mean in a AP will be the middle most term (Odd numbers) = t113= 100+112*4= 548 IMO C

Archit3110 · Answer

total terms of 3 digit no divisible by 4 ; 100 to 996 ; 996-100 +1 ; 225
and sum of these 225 terms ; 
sn=225/2* ( 2*225+(224*4) = 548*225
sum / total terms = mean ;; 548*225/225 = 548
IMO C

moropa2018 · Answer

I did it this way.... since all numbers in the set are divisible by 4, mean should also be divisible by 4. Only 548 is divisible by 4 among all the options. Can anybody tell me if my approach is right or not?

Additya · Answer

Can we directly select option C as the answer because it is the only option perfectly divisible by 4 (as all 3 digits are divisible by 4 there mean should also be divisible by 4) ?

nicolasbrina · Answer

Hi! I did the same thing, but don't know if it is the correct approach, could be not because in the formulas the number has to be divisible by 2, but nothing is said about 4. maybe someone can help

If set Q consists of all three digit numbers divisible by 4, what is

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If set Q consists of all three digit numbers divisible by 4, what is

Prep Toolkit

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