What is the sum of first 10 non-negative even integers? A) 40 B) 60 C

Question

What is the sum of first 10 non-negative even integers? A) 40 B) 90 C) 100 D) 110 E) 200 Source: www.GMATinsight.com

BrentGMATPrepNow · Accepted Answer

Another approach....

We want: 0 + 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18

Let's  add the 10 values in PAIRS ,  starting with the two outermost values and working inwards.  
Notice that 0 + 18 = 18
And 2 + 16 = 18
And 4 + 14 = 18
In fact, when we add the values like this, every pair adds to 18

There are 10 values, so there are 5 pairs (all of which add to 18)
So, the sum = 5 x 18 = 90

Answer:  B

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sashiim20 · Answer

First 10 Non - negative numbers  = 0,1,2,3,4,5,6,7,8,9

First 10 Non - negative even numbers  = 0,2,4,6,8,10,12,14,16,18

Properties of zero :

1) Zero is even

2) Zero is neither positive nor negative.

Sum of first n positive even numbers  = n (n + 1)

Sum of first 9 positive even numbers  = 9 (9 + 1) = 9 * 10 = 90.

Therefore sum of first 10 non-negative even integers  = 90 + 0 = 90.  Answer (B)...

chetan2u · Answer

Hi,
A method to calculate if you do not know the formula n(n+1) is ...
First number=0..
Tenth number = 0+(10-1)*2=18, 10 is total numbers and 2 is the difference between consecutive integers.

So mean =  \frac{0+18}{2}=9 ..
Sum = 9*10=90
B

JeffTargetTestPrep · Answer

The first 10 non-negative even integers are from 0 to 18.
 
The average of those integers is (0 + 18)/2 = 18/2 = 9.
 
Thus, the sum of those integers is 9 x 10 = 90.
 
Answer: B

arvind910619 · Answer

imo b 
this is a tricky question as we are asked sum of first 10 non negative even integers , so we have to include 0 .
our numbers will be 0 2 4 6 8 10 12 14 16 18 
sum =10/2(0+18)=90

shashankism · Answer

First 10 non-ve even integers area : 0, 2, 4,6, 8, .... 18 
Sum = 0+2+4+6+8+....+18
=2(0+1+2+3+4......+9)
90
 Answer B.

sasyaharry · Answer

Adding pairs we get 18*5=90

pushpitkc · Answer

The sum of the first 10 even integers is given by formula  n(n+1)

Since we have been asked the sum of the first non-negative even integers, it includes 0 as well.
So in essence, we need to find the sum of the first 9 even integers, which is  9(9+1)  = 90(Option B)

Coach75 · Answer

Hi Brent,

Grateful for your guidance on how to apply the formula : n(n+1)/2

Thank you for your help in advance
Best Regards
Fatima-Zahra

bumpbot · Answer

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What is the sum of first 10 non-negative even integers? A) 40 B) 60 C

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What is the sum of first 10 non-negative even integers? A) 40 B) 60 C

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