1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
serg [7]
3 years ago
14

Three printing presses, R, S, and T, working together at their respective constant rates, can do a certain printing job in 4 hou

rs. S and T, working together at their respective constant rates, can do the same job in 5 hours. How many hours would it take R, working alone at its constant rate, to do the same job?
A. 8
B. 10
C. 12
D. 15
E. 20
Mathematics
1 answer:
zmey [24]3 years ago
3 0

Answer:

20(E)

Step-by-step explanation:

Printing press R, S and T are working together at their respective constant rate.

They can do a job for 4 hours.

Let r, s and t be the time for printing press R, S and T to complete the job alone at their respective constant rate.

Rate of printing press R = 1/r

Rate of printing press S = 1/s

Rate of printing press T = 1/t

Rate = job / time

R + S + T = 4

1/r + 1/s + 1/t = 1/4

S + T = 5

1/s + 1/t = 1/5

Substitute 1/s + 1/t = 1/5 in the equation 1/r + 1/s + 1/t = 1/4

1/r + 1/5 = 1/4

1/r = 1/4 - 1/5

1/r = (5 - 4)/ 20

1/r = 1/20

r = 20 hours

It takes the printing press R 20 hours to complete the job alone

You might be interested in
The area of the base of a cube is 36 in2.<br> What is the total surface area of the cube?
irina [24]
216 in^2 ( its 2 squared but that’s how I can write it on my phone)

All the sides of a cube are the same and there are 6 sides to a cube so if we have 36 as our are of the base then we just have to multiply that by 6

36 x 6= 216

4 0
3 years ago
for what values of A does the acute angle formed by the lines 3x+2y=10 and Ax-2y=3 have measure of 45 degree
Nonamiya [84]

Answer:

Step-by-step explanation:

8 0
2 years ago
5x+3y=9 in standard form
tamaranim1 [39]
The standard for is Y=-5/3x +3
8 0
3 years ago
9^2= 9.5^2 + 4^2 - 2 (9.5) (4) (cosR)<br><br> I'm trying to find out the angle measure of R
alexandr402 [8]
Sorry I can't solve it.

Firstly, the equation is wrong. It is supposed to be <span>81 ≠ </span><span>30.25

Second of all, this is the best I got </span>81= <span><span>−<span>76 <span>(<span>cos<span>(r) </span></span></span></span></span>+ <span>106.25</span></span>
5 0
3 years ago
Identify the correct equation from the graph.
Margarita [4]

Answer:

I think is D

Step-by-step explanation:

3 0
2 years ago
Other questions:
  • Evaluate 3a2 + 4b2 for a = 2 and b = 3
    6·1 answer
  • What is the formula for the following arithmetic sequence? 12, 6, 0, -6, ...
    9·2 answers
  • Describe in your own words how you can recognize the difference between exponential growth and exponential decay
    5·1 answer
  • An ASB Robusta 300 TS sump pump can remove water from Martha's flooded basement in 70 min .The 1 Little Giant 1-A sump pump can
    8·1 answer
  • All possible square root of 100
    15·1 answer
  • Martha compra 2 kilos de tomate y 1 kilo de cebolla pagando S/ 8,40. Si la siguiente semana compra 1 kilo de tomate y 2 kilos de
    15·1 answer
  • In how many ways can a
    5·1 answer
  • In order to study the relationship between playing football and traumatic brain injuries, researchers placed accelerometers in t
    9·1 answer
  • Alicia wants to buy a carpet to cover her whole living room, except for the tiled floor. The tiled floor is 6 1/2 ft. by 3 1/4 f
    7·2 answers
  • Name a pair of complementary angles in this figure.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!