Ask question

Ask question

All categories

3 years ago

5

If I can paint a wall in 20 min and my friend can paint a wall in 30 min. How many minutes would it take for us to paint a wall

working together.

1 answer:

ra1l [238]3 years ago

3 0

Answer: $12\ \text{min}$

Step-by-step explanation:

Given

It takes 20 min and 30 min for a person and his friend to paint a wall individually i.e.

In 1 min they cover $\frac{1}{20}$ part and $\frac{1}{30}$ part of wall respectively.

If the work together, 1 minute work is

$\Rightarrow \dfrac{1}{20}+\dfrac{1}{30}\\\\\Rightarrow \dfrac{3+2}{60}\\\\\Rightarrow \dfrac{5}{60}$

Time required will be reciprocal of it

$\Rightarrow \dfrac{60}{5}=12\ \text{min}$

You might be interested in

A sandbox in the shape of a rectangular prism is 2 feet deep and 6 feet wide. Filled to the top it can hold 72 cubic feet of san

Sedbober [7]

Answer:

height=6 ft

Step-by-step explanation:

-The volume of a rectangular prism is given by the formula:

$V=lwh$

#We make h the subject of the formula the solve for it:

$V=lwh\\\\\frac{V}{lw}=h\\\\\therefore h=\frac{V}{lw}$

#Substitute to solve for height:

$h=\frac{V}{lw}\\\\=\frac{72}{2\times 6}\\\\=6\ ft$

Hence, the prism has a height of 6 ft.

6 0

2 years ago

What is 6,4 rounded to the nearest whole number

Aleks04 [339]

6.4 rounded to the nearest whole number will be 6.

if the decimal was 5 or larger, it would’ve been 7.

6 0

2 years ago

The ratio of boys to girls in Miss Smith’s class is 3 to 5. There are 15 girls in the class. What is the total number of student

pogonyaev

Answer:

9 boys

Step-by-step explanation:

15/5

=3

3*3

=9

3 0

2 years ago

Make a proof ( Statements and reasons )

frosja888 [35]

Step-by-step explanation:

They are equal because when we flip or reflect ABC onto DCB we are going to have the same size and the same shape

4 0

3 years ago

A2+5a+6=0<br><img src="https://tex.z-dn.net/?f=%20%7Ba%7D%5E%7B2%7D%20%20%2B%205a%20%2B%206%20%3D%200" id="TexFormula1" title="

Katarina [22]

we are given

$a^2+5a+6=0$

we can use factoring formula

$a^2-(m+n)a+mn=(a-m)(a-n)$

we can compare

and we get

$m+n=-5$

$mn=6$

now, we can solve for m and n

and we get

$m=-3 , n=-2$

now, we can use formula

and we get

$a^2+5a+6=(a+3)(a+2)$

now, we can set it equal to 0

$a^2+5a+6=(a+3)(a+2)=0$

$(a+3)=0$

$a=-3$

$a+2=0$

$a=-2$

so, we will get

$a=-2,a=-3$ .............Answer

3 0

2 years ago

Read 2 more answers