Answer: the answers are the second one and the last one
Step-by-step explanation:
Answer:
1 hour
Step-by-step explanation:
The speed ratio is ...
... truck : car = 1 : 1.5
Then the ratio of truck speed to the sum of their speeds is ...
... truck : combined = 1 : (1+1.5) = 1 : 2.5
Since time is inversely proportional to speed, the two vehicles will meet after 1/2.5 times the time the truck takes to cover the distance. That is ...
... (2.5 hours)/2.5 = 1 hour
_____
The truck speed is 145 mi/(2.5 h) = 58 mi/h.
The car speed is 1.5 × 58 mi/h = 87 mi/h.
Their combined speed is 58 + 87 = 145 . . . . mi/h.
So, they will cover the 145 mile distance in 1 hour.
Answer:
1.778 times more or 16/9 times more
Step-by-step explanation:
Given:
- Mirror 1: D_1 = 8''
- Mirror 2: D_2 = 6"
Find:
Compare the light gathering power of an 8" primary mirror with a 6" primary mirror. The 8" mirror has how much light gathering power?
Solution:
- The light gathering power of a mirror (LGP) is proportional to the Area of the objects:
LGP ∝ A
- Whereas, Area is proportional to the squared of the diameter i.e an area of a circle:
A ∝ D^2
- Hence, LGP ∝ D^2
- Now compare the two diameters given:
LGP_1 ∝ (D_1)^2
LGP ∝ (D_2)^2
- Take a ratio of both:
LGP_1/LGP_2 ∝ (D_1)^2 / (D_2)^2
- Plug in the values:
LGP_1/LGP_2 ∝ (8)^2 / (6)^2
- Compute: LGP_1/LGP_2 ∝ 16/9 ≅ 1.778 times more
(13x² + 5x) + 8x²
= (13 + 8)x² + 5x
= 21x² + 5x
Answer:
If in a company, 55% of workers are men, then,
100%-55%=45% in the company aren't men.
If x be the total number of workers in the company, then
45% of x=those who aren't men
45/100*x=1305
x=2900
Therefore, the total number of workers is 2900.