How do you solve this

Suppose it takes 45 hours for robot A to construct a new robot. Working together with robot B, it takes 25 hours for both robots

Len [333]

Answer:

56 hours 25 minutes

Step-by-step explanation:

Given:

Suppose it takes 45 hours for robot A to construct a new robot

It takes 25 hours for both robots to construct a new robot.

Question asked:

How long would it take robot B to construct a new robot, working alone ?

Solution:

Let the time taken by robot B to construct new robot = $x$

By robot A

It takes 45 hours to construct = 1 new robot

It takes 1 hour to construct = $\frac{1}{45} \ new\ robot$

By robot B

It takes $x$ hours to construct = 1 new robot

It takes 1 hour to construct = $\frac{1}{x}$ new robot

By working together

It takes 25 hours to construct = 1 new robot

It takes 1 hour to construct = $\frac{1}{25} \ new\ robot$

$\frac{1}{25}$ new robot is constructed in = 1 hour

New robot is constructed by both working together in 1 hour = New robot is constructed by robot A in 1 hour + New robot is constructed by robot B in 1 hour

$\frac{1}{25} =\frac{1}{45} +\frac{1}{x} \\$

Subtracting both sides by $\frac{1}{45}$

$\frac{1}{25}-\frac{1}{45} =\frac{1}{45} -\frac{1}{45}+\frac{1}{x} \\\\\frac{1}{25}-\frac{1}{45} =\frac{1}{x}\\\\ Taking\ LCM \ of \ 25\ and\ 45,\ we\ got\ 225$

$\frac{9-5}{225} =\frac{1}{x} \\ \\ \frac{4}{225} =\frac{1}{x}\\\\ By\ cross \ multiplication\\4\times x=225\\Dividing\ both\ sides\ by\ 4\\x=56.25\ hours$

Thus, robot B would take 56 hours 25 minutes to construct a new robot, working alone.

4 0

3 years ago

Read 2 more answers

Write the monomial in standard form. name it's coefficient and identify its degree.

Hunter-Best [27]

Answer:

$Standard\ Form = {3n^2} m^{-2}$

Step-by-step explanation:

Given

$\frac{2}{3m^2n} * 4.5n^3$

Required

Write in Standard Form

To start with; the two monomials have to be multiplied together;

$\frac{2}{3m^2n} * 4.5n^3$

$Standard\ Form = \frac{2 * 4.5n^3}{3m^2n}$

Split the numerator and the denominator

$Standard\ Form = \frac{2 * 4.5 * n^3}{3 * m^2 * n}$

Multiply Like terms

$Standard\ Form = \frac{9 * n^3}{3 * m^2 * n}$

Divide 9 by 3 to give 3

$Standard\ Form = \frac{3 * n^3}{m^2 * n}$

Divide n³ by n to n²

$Standard\ Form = \frac{3 * n^2}{m^2 }$

Split fraction

$Standard\ Form = {3 * n^2} * \frac{1}{m^2 }$

From laws of indices;

$\frac{1}{a^n} = a^{-n}$

$Standard\ Form = {3 * n^2} * \frac{1}{m^2 }$ becomes

$Standard\ Form = {3 * n^2} * m^{-2}$

Multiply all together

$Standard\ Form = {3n^2} m^{-2}$

5 0

3 years ago

Andrew took a math test with 40 questions. If he scored an 85%, how many questions did he get correct?

puteri [66]

Andrew answered 34 questions correctly.
I got the answer by divided the 85% by 100% (100% because it's the total percentage.) I received 0.85 when dividing that. Then, I took the 0.85 and divided it by the total of 40 questions, and that gave me the answer of 34.

4 0

3 years ago

Bill booked a ride to the airport. If it rains, the traffic will be bad and the probability that he will miss his flight is 0.06

kvasek [131]

Answer:0.614

Step-by-step explanation:

Given

Probability he will miss flight if it rains=0.06

Probability he will miss flight it does not rain=0.01

Given the probability of rain=0.21

Therefore Probability that it will not rain=1-0.21=0.79

Probability that he will miss the flight $=0.21\times 0.06+0.79\times 0.01=0.0205$

P(actual raining and he missed the flight| he miss the flight) $=\frac{0.21\times 0.06}{0.21\times 0.06+0.79\times 0.01}$

$=\frac{0.0126}{0.0205}=0.614$

7 0

3 years ago

At Pizzazz Pizza, the total price for 5

ira [324]

Answer:

The answer to your question is $9.5

Step-by-step explanation:

Data

Large pizza = L

Medium pizza = m

Write equation for both situations

Situation 1 5L + 2m = 81.5

Situation 2 4L + 3m = 78.5

Solve the system of equation by elimination

Multiply situation 1 by -3 and situation 2 by 2

-15L - 6m = -244.5

8L + 6m = 157

-7L = -87.5

Solve for L L = -87.5/-7

L = $12.5

Substitute L in Situation 1 to find m

5(12.5) + 2m = 81.5

62.5 + 2m = 81.5

2m = 81.5 - 62.5

2m = 19

m = 19/2

m = $ 9.5

The prize of a medium pizza is $9.5

8 0

3 years ago