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OverLord2011 [107]

3 years ago

12

If Jeff washes his car in 6 minutes and bob washes the same car in 8 minutes. How long does it take both of them to wash the sam

e car?

2 answers:

Tatiana [17]3 years ago

8 0

Answer:

3 3/7 or 24/7 mins

Step-by-step explanation:

Let total job = X

Jeff's rate = X/6

Bob's rate = X/8

Combined rate = X/6 + X/8

(4X × 3X)/24 = 7X/24

7X/24 = X/T

T = X ÷ (7X/24)

T = X × (24/7X)

T = 24/7 mins

Shortcut:

T = product of individual times/sum of individual times

T = (6×8)/(6+8)

T = 48/14

T = 24/7

T = 3 3/7 mins

pishuonlain [190]3 years ago

4 0

Answer:

3 3/7 minutes or 3.4mins

Step-by-step explanation:

If Jeff washed husband car in 6 minutes and Bob washed the same car in 8 minutes , the time taken by both of them in washing the car ?

If Jeff washed the car in 6 minutes , in one minute, Jeff’s work = 1/6

If bob washed in 8mins, in one minute, bob’s work = 1/8

Add both together

1/6 + 1/8

Lcm of 6 and 8 Is 24

Divide the Lcm by the denominators and multiply the results by the numerator

We have 4+3 /24

7/24

Therefore time taken by both of them in Washing is 24/7

= 3 3/7 minutes 0r 3.4mins

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Determine whether each expression is equivalent to 49^2t – 0.5.

vampirchik [111]

Answer:

None of the expression are equivalent to $49^{(2t - 0.5)}$

Step-by-step explanation:

Given

$49^{(2t - 0.5)}$

Required

Find its equivalents

We start by expanding the given expression

$49^{(2t - 0.5)}$

Expand 49

$(7^2)^{(2t - 0.5)}$

$7^2^{(2t - 0.5)}$

Using laws of indices: $(a^m)^n = a^{mn}$

$7^{(2*2t - 2*0.5)}$

$7^{(4t - 1)}$

This implies that; each of the following options A,B and C must be equivalent to $49^{(2t - 0.5)}$ or alternatively, $7^{(4t - 1)}$

A. $\frac{7^{2t}}{49^{0.5}}$

Using law of indices which states;

$a^{mn} = (a^m)^n$

Applying this law to the numerator; we have

$\frac{(7^{2})^{t}}{49^{0.5}}$

Expand expression in bracket

$\frac{(7 * 7)^{t}}{49^{0.5}}$

$\frac{49^{t}}{49^{0.5}}$

Also; Using law of indices which states;

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

$\frac{49^{t}}{49^{0.5}}$ becomes

$49^{t-0.5}}$

This is not equivalent to $49^{(2t - 0.5)}$

B. $\frac{49^{2t}}{7^{0.5}}$

Expand numerator

$\frac{(7*7)^{2t}}{7^{0.5}}$

$\frac{(7^2)^{2t}}{7^{0.5}}$

Using law of indices which states;

$(a^m)^n = a^{mn}$

Applying this law to the numerator; we have

$\frac{7^{2*2t}}{7^{0.5}}$

$\frac{7^{4t}}{7^{0.5}}$

Also; Using law of indices which states;

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

$\frac{7^{4t}}{7^{0.5}}$ = $7^{4t - 0.5}$

This is also not equivalent to $49^{(2t - 0.5)}$

C. $7^{2t}\ *\ 49^{0.5}$

$7^{2t}\ *\ (7^2)^{0.5}$

$7^{2t}\ *\ 7^{2*0.5}$

$7^{2t}\ *\ 7^{1}$

Using law of indices which states;

$a^m*a^n = a^{m+n}$

$7^{2t+ 1}$

This is also not equivalent to $49^{(2t - 0.5)}$

6 0

3 years ago

A spherical tank has a radius of 6 yards. It is filled with a liquid the cost $7.15 per cubic yard.

mote1985 [20]

We have two questions, but we need to find the volume of the spherical tank first.
So the formula we will use to find the volume is:
(4/3)πr³=V
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(4/3)(3.14)6³
(4/3)(3.14)(216)
4.1867×216
I'll be using the repeating decimal for 4.1867, I rounded to 7, but there is a repeating 6.
904.32
So the volume is 904.32 yards³ (or 904.78 if using the full pi)
We have to multiply the volume by 7.15.
904.32×7.15
6,465.89
It will cost $6,465.89 to fill the tank with the liquid.

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Step-by-step explanation:

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Gf(x)
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