Answer:
2 hrs 13 mins
Step-by-step explanation:
If Richard can paint the living room in 4 hrs, then in 1 hour he can paint 1/4 of the living .
If Vanessa can paint the living room in 5 hours, then in one hour, she can paint 1/5 of the living room.
In one hour Richard and Vanessa can paint 1/4 + 1/5 = 1/y
y is the number of hours it will take both Richard and Vanessa to paint the living room. 1/y is how much of the house they can paint in one hour.
1/4 + 1/5 = 1/y
(5 + 4)/20. ( find the LCM)
9/20 = 1/y
9y= 20
y = 20/9
y = 2.22hrs
y = 2 hrs 13 mins
Solution :
a).
Given : Number of times, n = 25
Sigma, σ = 0.200 kg
Weight, μ = 13 kg
Therefore the hypothesis should be tested are :


b). When the value of 
Test statics :



= 45.5
P-value = 2 x P(Z > 45.5)
= 2 x 1 -P (Z < 45.5) = 0
Reject the null hypothesis if P value < α = 0.01 level of significance.
So reject the null hypothesis.
Therefore, we conclude that the true mean measured weight differs from 13 kg.
Answer:

Step-by-step explanation:
When you simplify the numerator and the denominator, you find they both have denominators of xy. So, the ratio of those is the ratio of their numerators.

Answer:
15 and 21
Step-by-step explanation:
Given the n th term formula
T = 2n + 5
To find the 5 th and 8 th terms substitute n = 5 and n = 8 into the formula
= (2 × 5) + 5 = 10 + 5 = 15
= (2 × 8) + 5 = 16 + 5 = 21