Hello :
all n in N ; n(n+1)(n+2) = 3a a in N or : <span>≡ 0 (mod 3)
1 ) n </span><span>≡ 0 ( mod 3)...(1)
n+1 </span>≡ 1 ( mod 3)...(2)
n+2 ≡ 2 ( mod 3)...(3)
by (1), (2), (3) : n(n+1)(n+2) ≡ 0×1×2 ( mod 3) : ≡ 0 (mod 3)
2) n ≡ 1 ( mod 3)...(1)
n+1 ≡ 2 ( mod 3)...(2)
n+2 ≡ 3 ( mod 3)...(3)
by (1), (2), (3) : n(n+1)(n+2) ≡ 1×2 × 3 ( mod 3) : ≡ 0 (mod 3) , 6≡ 0 (mod)
3) n ≡ 2 ( mod 3)...(1)
n+1 ≡ 3 ( mod 3)...(2)
n+2 ≡ 4 ( mod 3)...(3)
by (1), (2), (3) : n(n+1)(n+2) ≡ 2×3 × 4 ( mod 3) : ≡ 0 (mod 3) , 24≡ 0 (mod3)
Answer:
30.5 ; 49 ; 27 ; 50 ; 45
Step-by-step explanation:
Determine the first and third quartiles. Determine the second decile and the eighth decile. Determine the 67th percentile
Given the ordered data :
13 13 13 20 26 27 29 32 34 34 35 35 36 37 38 41 41 41 42 44 46 47 48 50 53 55 56 62 67 82
Sample size, n = 30
The first quartile ;Q1
Q1 = 1/4(n+1)th term
Q1 = 31/4 = 7.75th term
Q1 = (29+32)/2
Q1 = 30.5
Q3 ;
Q3 = 3/4(n+1)th term
Q3 = 3(31)/4 = 23.25 th term
Q3 = (48 + 50) /2 = 49
2nd decile :
0.2 * (nth term
0.2 * 30 = 6th term = 27
8th decile :
0.8 * 30 = 24 th term
= 50
67th percentile :
0.67 * (n+1)th term
0.67 * 31 = 20.77
= (44 + 46) / 2
= 45
Answer:
H. the number of orchestra seat is 900
Step-by-step explanation:
Step one:
let the number of orchestra seat be x
and balcony seat be y
cost of orchestra= $50 each
cost of balcony =$40 each
total tickets= 1500
x+y= 1500----------1
amount earned= $69000
50x+40y=69000--------2
The system of equation for the situation is
x+y= 1500----------1
50x+40y=69000--------2
from 1, x=1500-y
put this in equation 2
50(1500-y)+40y=69000
75000-50y+40y=69000
-10y=69000-75000
-10y=-6000
divide both sides by -10
y=-6000/-10
y=600
put y= 600 in equation 1
x+600= 1500
x=1500-600
x=900
Answer:
Therefore the population will be maximum when x=30 inches.
Step-by-step explanation:
Given that, the mosquito population is a function of rainfall and can be approximated by the formula
where x is the number of inches of rainfall.
Differentiating with respect to x
Again differentiating with respect to x
Now we set N'(x)=0
Since at x=30, N''(x)<0, So at x=30, N(x) has maximum value.
Therefore the population will be maximum when x=30 inches.
Answer:
10
Step-by-step explanation:
4m=40
m=10
