What is the sum of all multiples of 3 between 100 and 300
Answers
Answered by
2
Answer:
13167
This assume we mean "strictly between", so not including 300.
If you wanted to included 300, just add 300 to this answer to get 13467.
Hope this helps.
Step-by-step explanation:
102 + 105 + 108 + ... + 291 + 294 + 297
= 102 + 105 + 108 + ... + 198
+ 297 + 294 + 291 + .... + 201
= (102+297) + (105+294) + (108+291) + ... + (198+201)
= 399 + 399 + 399 + .... + 399
= 33 × 399
= 13167
Anonymous:
Where does the 33 come from? The number of terms from 102 to 297 is (297-102)/3+1 = 195/3+1 = 65+1=66. Once they're paired up to make the 399s, there are 66/2=33 of these.
Plz mark this the Brainliest answer!
Answered by
8
Answer:
Step-by-step explanation:S{102,105,108.......297}
a=102
Tn=297
d=3
n=?
Tn=a+(n-1)d
297=102+(n-1)d
297-102=(n-1)3
195=(n-1)3
195/3=(n-1)
65=n-1
65+1=n
Therefore, n=66
Now, Sn=n/2(a+Tn)
Sn=66/2(102+297)
Sn=33(399)
Sn=13,167
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