Answer:
a. Mean = 20
Sd = 4
b. Probability of X = 20 = 0.1960
Step-by-step explanation:
we have
n = 25
p = 80% = 0.8
mean = np
= 0.8 * 25
= 20
standard deviation = √np(1-p)
= √25*0.8(1-0.8)
=√4
= 2
probability that exactly 20 favours ban
it follows a binomial distribution
= 25C20 × 0.8²⁰ × 0.2⁵
= 53130 × 0.01153 × 0.00032
= 0.1960
Probability of X = 20 = 0.1960
The formula for the sum of n terms in an arithmetic progression is:
S = n/2 * (2a + (n-1)d)
Here, the common difference, d, is 8 and the first term, a, is 1. Substituting these into the formula, we get:
S = n/2 * (2*1 + 8(n - 1))
S = n + 4n² - 4n
S = 4n² - 3n
The answer is A.
Answer:
2x - 10 = 10 - 3x
Simplifying
2x + -10 = 10 + -3x
Reorder the terms:
-10 + 2x = 10 + -3x
Solving
-10 + 2x = 10 + -3x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '3x' to each side of the equation.
-10 + 2x + 3x = 10 + -3x + 3x
Combine like terms: 2x + 3x = 5x
-10 + 5x = 10 + -3x + 3x
Combine like terms: -3x + 3x = 0
-10 + 5x = 10 + 0
-10 + 5x = 10
Add '10' to each side of the equation.
-10 + 10 + 5x = 10 + 10
Combine like terms: -10 + 10 = 0
0 + 5x = 10 + 10
5x = 10 + 10
Combine like terms: 10 + 10 = 20
5x = 20
Divide each side by '5'.
x = 4
Simplifying
x = 4
No he walks 7/10 of a mile
you have to make 2/5 have a common denominator with 3/10
so 2×2=4 (numerator)
2×5=10 (denominator)
4/10+3/10= 7/10
since you only add the numerator because the denominator makes it a like term
