Problems on Numbers
1. The average of 4 consecutive even numbers is 29. Find the largest of these numbers.
Solution:
Let the 4 consecutive even numbers be x,(x+2),(x+4) and (x+6).
Average = sum of the observations / Number of observations
29 = [x+(x+2)+(x+4)+(x+6)] / 4
116 = 4x+12
104= 4x
x=26.
The 4 numbers are 26, 28, 30, 32.
Here the largest one is 32.
2. The sum of the squares of the 3 consecutive odd numbers is 83. Find the numbers.
Solution:
Let the numbers be x, (x+2) and (x+4).
x2+(x+2)2+(x+4)2=83 [Given]
x2+x2+4x+4+x2+8x+16 = 83
3x2+12x+ 20= 83
3x2+12x- 63 = 0
x2+4x-21=0
(x+7)(x-3)=0
x= 3, -7
x=3 (Considering the postive value)
The numbers are 3, 5 and 7.
1. The average of 4 consecutive even numbers is 29. Find the largest of these numbers.
Solution:
Let the 4 consecutive even numbers be x,(x+2),(x+4) and (x+6).
Average = sum of the observations / Number of observations
29 = [x+(x+2)+(x+4)+(x+6)] / 4
116 = 4x+12
104= 4x
x=26.
The 4 numbers are 26, 28, 30, 32.
Here the largest one is 32.
2. The sum of the squares of the 3 consecutive odd numbers is 83. Find the numbers.
Solution:
Let the numbers be x, (x+2) and (x+4).
x2+(x+2)2+(x+4)2=83 [Given]
x2+x2+4x+4+x2+8x+16 = 83
3x2+12x+ 20= 83
3x2+12x- 63 = 0
x2+4x-21=0
(x+7)(x-3)=0
x= 3, -7
x=3 (Considering the postive value)
The numbers are 3, 5 and 7.
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