B = hourly rate for babysitting and w = hourly rate for working at water park
3b + 10w = 109...multiply by -8
8b + 12w = 177...multiply by 3
----------------------
-24b - 80w = - 872 (result of multiplying by -8)
24b + 36w = 531 (result of multiplying by 3)
---------------------add
- 44w = - 341
w = -341/-44
w = 7.75 <=== hourly rate for working at water park
3b + 10w = 109
3b + 10(7.75) = 109
3b + 77.50 = 109
3b = 109 - 77.50
3b = 31.50
b = 31.50/3
b = 10.50 <== hourly rate for babysitting
Answer:
t = 
Step-by-step explanation:
Given that t varies inversely as the square root of u then the equation relating them is
t = 
← k is the constant of variation
To find k use the condition t = 3 when u = 4, thus
k = t
= 3 × 
= 3 × 2 = 6
t = 
← equation of variation
When u = 49, then
t = 
=
Answer:
C
Step-by-step explanation:
In this question, we are interested in calculating the z-score of a company employee.
Mathematically;
z-score = (x- mean)/SD
where in this case;
x is the value given which turns out to be the annual salary of the employee = 28,000
Mean = 34,000
standard deviation = 4,000
Plugging these values into the equation above, we have;
z-score = (28000-34000)/4000 = -6000/4000 = -1.5
Step 1:
<span>Calculate the effective thermal conductivity of the wall or ceiling:
</span>
K_eff = [ (13 ÷ 8)(0.12) + (16 - (13 ÷ 8)) × (0.04)] ÷ 16
K_eff =<span> [ 0.195 + 0.565] </span>÷<span> 16
</span>
K_eff = 0.76 ÷ 16
K_eff = 0.0475 W/ (m K)
Step 2:
Calculate <span>the interior ceiling area:
</span>Area of each of the interior side walls = <span>8.82 m x 8.64 m
= 76.2 m</span>²
Area of the interior ceiling = 8.64 m × <span>8.64 m
</span> = 74.6 m²
H = - k·A·(Δ - T) ÷ <span>(thickness)
</span>
H = - 0.0475 ÷ (379.45 × 20) ÷ 45/8
H = - ( - 0.95 × 379.45 ) ÷<span> 0.1429
</span>
H = <span>2.52 kW </span>
