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CarltonLeach

Maths Thread

5 posts in this topic

Finding Sums of N Terms (Sn)

1) 1+2+3+....+98+99+100 = 101 x 50 = 5050

2) 1+2+..+(n-2) + (n-1) = n (n-1/2)

In step one can you tell me where the 101 and 50 comes from?

I take it the numberrs are going up in 1's?

Could someone explain the next bit

Bit lost here

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STEP ONE ) the first space could be 4747 --------------- 1 + 2 + 3 + 4747 + 98 + 99 + 100 = 5050 which is 101 x 50 haven't done a good maths sum in years . I could be wrong though

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Finding Sums of N Terms (Sn)

1) 1+2+3+....+98+99+100 = 101 x 50 = 5050

2) 1+2+..+(n-2) + (n-1) = n (n-1/2)

In step one can you tell me where the 101 and 50 comes from?

I take it the numberrs are going up in 1's?

Could someone explain the next bit

Bit lost here

tumblr_liwb2glVzZ1qb2w3e.gif

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Finding Sums of N Terms (Sn)

1) 1+2+3+....+98+99+100 = 101 x 50 = 5050

2) 1+2+..+(n-2) + (n-1) = n (n-1/2)

In step one can you tell me where the 101 and 50 comes from?

I take it the numberrs are going up in 1's?

Could someone explain the next bit

Bit lost here

1+100=101, 2+99=101.....

So you got 50 pairs of numbers which equal 101. Total =101x50.

If you sum from 1 to an even number, you can write this out out generally as n(n-1)/2. Where n=(1 + largest even number).

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Finding Sums of N Terms (Sn)

1) 1+2+3+....+98+99+100 = 101 x 50 = 5050

2) 1+2+..+(n-2) + (n-1) = n (n-1/2)

In step one can you tell me where the 101 and 50 comes from?

I take it the numberrs are going up in 1's?

Could someone explain the next bit

Bit lost here

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