AP
The sum of all two digit even
numbers from 10 to 98 is
Answers
Answered by
2
Answer:
2430
Step-by-step explanation:
S = 10 + 12 + ... + 98
= 2(5 + 6 + ... + 49)
= 2([1 + 2 + 3 + 4 + 5 + 6 + .. + 49] - [1 + 2 + 3 + 4])
= 2(49(50)/2 - 4(5)/2)
= 49(50) - 4(5)
= 2450 - 20
= 2430
I used the fact that the sum of the natural numbers from 1 to N inclusive is N(N+!)/2.
Answered by
2
Answer:
S = 10 + 12 + ... + 98
= 2(5 + 6 + ... + 49)
= 2([1 + 2 + 3 + 4 + 5 + 6 + .. + 49] - [1 + 2 + 3 + 4])
= 2(49(50)/2 - 4(5)/2)
= 49(50) - 4(5)
= 2450 - 20
= 2430
Step-by-step explanation:
Similar questions