Х+ 2y = -1<br> 2x – Зу = 12

pls solve quickly!: It took a boat 2 hours to reach town A going upstream. The way back was 1h20 min. What is the speed of the b

goldenfox [79]

Answer:

15 mph

Step-by-step explanation:

Given: Boat took 2 hours to reach Town A going upstream.

Speed of stream= 3 mph

Time taken to reach back home= 1 hours 20 minutes

Lets assume distance covered one side be "d" and speed of boat in still water be "s".

∴ Speed of boat in upstream= $(s-3) \ mph$

Speed of boat in downstream= $(s+3)\ mph$

Also converting into fraction of time taken to reach back home.

Remember; 1 hour= 60 minutes

∴ Time taken to reach back home= $60+20= 80\ minutes$

Converting time given into fraction= $\frac{80\ minutes}{60\ minutes} = \frac{4}{3} \ hours$

hence, Time taken to reach back home is $\frac{4}{3} \ hours$

Now forming equation of boat travelling upstream and downstream, considering distance remain constant.

We know, $Distance= speed \times time$

⇒ $(s-3)\times 2= (s+3)\times \frac{4}{3}$

Using distributive property of multiplication

⇒ $2s-6= \frac{4}{3}s +4$

subtracting both side by $\frac{4}{3} s$

⇒ $2s-\frac{4}{3} s-6= 4$

Adding both side by 6

⇒ $2s-\frac{4}{3} s= 10$

taking LCD as 3

⇒ $\frac{2}{3} s= 10$

Multiplying both side by $\frac{3}{2}$

⇒ $s= \frac{3}{2} \times 10$

∴s= 15 mph

Hence, 15 mph is the speed of the boat in still water.

8 0

3 years ago

Fill in the steps to solve the log log base x of (2x)^3=6

arsen [322]

Answer:

x=2

Step-by-step explanation:

logx (2x)^3 = 6

We can rewrite without the exponent

3 logx (2x) = 6

Divide by 3

3/3 logx (2x) = 6/3

logx (2x) = 2

Raise each side to the base x

x^ logx (2x) =x^ 2

2x = x^2

Subtract 2x from each side

2x-2x = x^2 -2x

0 = x^2 -2x

Factor an x

0 = x(x-2)

Using the zero product property

x =0 x-2 =0

x =0 x=2

We cannot have a base of 0, so x cannot equal 0

x=2

6 0

3 years ago

A cuboid has side lengths 3cm, 4cm and 7cm. A cylinder with a height double that of the longest side of the cuboid has the same

mart [117]

Step-by-step explanation:

Longest side of cuboid: 7cm

Height of cylinder:

2 × 7 = 14 cm

Volume of cuboid:

7x3x4=84 $cm^3$

Volume of cylinder:

$84=14\pi r^2 \\r=\sqrt{\frac{6}{\pi} } \ \ \ cm\\r=1.38 \ cm\\$

Surface area of the cylinder:

$\pi r^2 + 2 \pi r h$

$6+2\pi (\sqrt{\frac{6}{\pi} } ) (14)$

=128 cm^2

4 0

3 years ago

What is 1.75 kilometres as a fraction of 700 metres? <br>Give your answer in its simplest form

aniked [119]

Answer:

5/2

Step-by-step explanation:

1000m = 1km

1.75km = 1750m

1750 / 700 = 5/2

7 0

3 years ago

Mallorie has $3 in her wallet.If this is 10% of her monthly allowance, What is her monthly allowance?

Mekhanik [1.2K]

Her monthly allowance is $30! hope this helped

8 0

3 years ago

Read 2 more answers

Х+ 2y = -1 2x – Зу = 12