The sum of 25 consecutive odd number is 1275.
Find the largest and smaller of these numbers.
2007-09-22 14:10:33 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
27 lowest and 75 highest
2007-09-22 14:27:45 · answer #1 · answered by Keith B 4 · 0⤊ 0⤋
The series is of the form (n+2) - each number is two more than the one before it.
Since there is an odd number of items in the series, you can find the center point by dividing 1275/25 = 51
Twelve of the numbers are larger and twelve are smaller than the center point, so
51 - 12*2 = 51-24 = 27 smallest
51 + 12*2 = 51+24 = 75 largest
2007-09-22 21:31:17 · answer #2 · answered by Steve A 7 · 0⤊ 0⤋
1275=n(2A0+(n-1)d)/2
1275(2)=2A0n+(n-1)nd
n=25 d=2
1275(2)=2A0(25)+(25-1)(25)(2)
A0=(2550-1200)/50=27
solve for a25
1275=25(27+a25)/2
1275(2)/25 -27=a25
a25=75
the largest is 75 and the smallest is 27
2007-09-23 02:06:13 · answer #3 · answered by ptolemy862000 4 · 0⤊ 0⤋