Given that 1 + 2 + 3 + ... + 10 = 55. Then (11 +
12 + 13 + ... +20) is equal to
a. 155 b. 135 c. 165 d. 160.
Answers
Answered by
3
Answer:
(11 + 12 + 13 + ... +20) = 155
Step-by-step explanation:
Given that 1 + 2 + 3 + ... + 10 = 55
We need to find
(11 + 12 + 13 + ... +20)
Now 11 = 10 + 1
12 = 10 + 2
13 = 10 + 3
.
.
20 = 10 + 10
=> (11 + 12 + 13 + ... +20) = 10 + 1 + 10 + 2 + 10+ 3 +.............................. + 10 + 10
= 10 * 10 + 1 + 2 + 3 + ... + 10
= 100 + 55
= 155
(11 + 12 + 13 + ... +20) = 155
Answered by
0
Answer:155 option a
Step-by-step explanation:
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