For any positive integer n, the sum of the first n positive integers equals ~$\frac{n\left ( n+1 \right )}{2}$~. What is the sum of all the even integers between 99 and 301?
10,100
20,200
22,650
40,200
45,150
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Average of the set: (largest+smallest)/2=(300+100)/2=200; # of terms: (largest-smallest)/2+1=(300-100)/2+1=101 The sum = 200*101= 20,200.
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Average of the set: (largest+smallest)/2=(300+100)/2=200;
# of terms: (largest-smallest)/2+1=(300-100)/2+1=101
The sum = 200*101= 20,200.
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