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2 years ago

11

Working alone, Elisa can sweep a porch in 11 minutes. Pranav can sweep the same porch in 13 minutes. How long would it take if t

hey worked together.
A. 5.96 Minutes
B. 5.86 Minutes
C. 5.21 Minutes
D. 4.87 Minutes

1 answer:

GaryK [48]2 years ago

5 0

Elisa, e = 11mins

Prenav,p = 13mins

time to complete, t

1 = t( 1/11 + 1/13) = t (24/143)

t = 143/24 = 5.96min

Answer is A 5.96mins

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A pipe of diameter 64mm discharges water at a rate of 2.05mm/s into an empty cylindrical tank of diameter 7.6cm and height 2.3m.

inessss [21]

Answer:

Diameter of pipe = D = 64mm

cross sectional Area of pipe= A = pi * (D/2)^2 = pi * (32)^2 = 1024pi mm^2

Discharge Rate of water = v = 2.05 mm/s

Volume of Cylinder = V = pi * (D/2)^2 * h = pi * (38)^2 * 2300 = 3321200pi mm^3

(Area of pipe)*(Rate) = (Volume) / (Time)

Time = T = (Volume) / [(Area of pipe)*(Rate)]

= (3321200pi)/(1024pi * 2.05)

= 1582.126524s

4 0

2 years ago

Benjamin is riding a unicycle. The tire of his unicycle has a circumference of 2.8 \text{ m}2.8 m2, point, 8, start text, space,

Karo-lina-s [1.5K]

Answer:

420 meters

Step-by-step explanation:

Q. Benjamin is riding a unicycle. The tire of his unicycle has a circumference of 2.8 m, and the tire revolves 1.5 times per second. What is the distance Benjamin travels in 100 seconds?

<u>Given</u>:

Circumference of circular tire = 2.8 meters

Tire revolves per second = 1.5 times

<u>Question asked:</u>

What is the distance Benjamin travels in 100 seconds?

<u>Solution:</u>

Circumference of circular tire means distance covered by the unicycle's tire when it revolves 1 time that is 2.8 meters.

<em><u>Now, by unitary method:</u></em>

In 1 second, tire revolves = 1.5 times

In 100 seconds, tire revolves = 1.5 $\times$ 100

= 150 times

Distance covered by the tire when it revolves 1 time = 2.8 m

Distance covered by the tire when it revolves 150 times = 2.8 $\times$ 150

= 420 meters

Therefore, Benjamin travels 420 meters in 100 seconds.

8 0

2 years ago

Read 2 more answers

if 1000 spherical of radius 1 cm are melted to form a bigger bulb. Then find the radius of bigger bulb

never [62]

Answer:

10 cm

Step-by-step explanation:

Given:

No. of small spherical bulb = 1,000

radius (r) of smaller bulbs = 1 cm

Required:

radius of the bigger bulb

SOLUTION:

The following equation represents the relationship of the volume of the smaller and bigger bulb,

$\frac{V_2}{V_1} = 1,000$

Where,

$V_2$ = volume of bigger bulb

$V_1$ = volume of smaller bulb

1,000 is the number of smaller bulbs melted to form the bigger bulb.

Volume of a sphere is given as, ⁴/3πr³

Therefore:

$V_2$ = ⁴/3*π*r³ = 4πr³/3

$V_1$ = ⁴/3*πr³ = ⁴/3*π*(1)³ = ⁴/3π*1 = 4π/3

Plug the above values into the equation below:

$\frac{V_2}{V_1} = 1,000$

$\frac{\frac{4*pie*r^3}{3}}{\frac{4*pie}{3}} = 1,000$

$\frac{4*pie*r^3}{3}*{\frac{3}{4*pie} = 1,000$

$\frac{4*pie*r^3*3}{3*4*pie} = 1,000$

$\frac{12*pie*r^3}{12*pie} = 1,000$

$r^3 = 1,000$ (12pie cancels 12 pie)

$r = 10$ (taking the cube root of each side)

Radius of the bigger bulb = 10 cm

3 0

2 years ago

The resale value of a textbook decreases by 25% with each previous owner. A new textbook is sold for $85. Which function represe

Alisiya [41]

A exponential function would represent it nicely f(x)=b*a^x
Reason being a decrease of %
a = 1+r
r = -25% = -0.25
And b being what the original cost of the book
f(x)=85*0.75^x
Where f(x) is the price after x amount of previous owners

9 0

2 years ago

Read 2 more answers

What is the simplified form of the following expression? 2 StartRoot 18 EndRoot + 3 StartRoot 2 EndRoot + StartRoot 162 EndRoot

ExtremeBDS [4]

Answer:

$18\sqrt2$

Step-by-step explanation:

To simplify:

$2 \sqrt{18}+ 3 \sqrt2+ \sqrt{162 }$

First of all, let us write 18 and 162 as product of prime factors:

$18 = 2 \times \underline{3 \times 3}\\162 = 2 \times \underline{3 \times 3} \times \underline{3 \times 3}$

The pairs are underlined as above.

While taking roots, only one of the numbers from the pairs will be chosen.

Now, taking square roots.

$\sqrt{18} =3 \sqrt2$

$162 = 3 \times 3 \times \sqrt 2 = 9 \sqrt2$

So, the given expression becomes:

$2 \sqrt{18}+ 3 \sqrt2+ \sqrt{162 } = 2 \times 3\sqrt2 + 3\sqrt2 +9\sqrt2\\\Rightarrow 6\sqrt2 + 3\sqrt2 +9\sqrt2\\\Rightarrow \sqrt2(6+3+9)\\\Rightarrow \bold{18\sqrt2}$

So, the answer is:

$18\sqrt2$ or 18 StartRoot 2 EndRoot

7 0

2 years ago