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3 years ago

13

A contractor digs a hole for the basements of a new house that is 40 feet long and 10 1/2 feet deep. What is the width of the ho

le if 6,510 cubic feet of dirt are removed?
A.80 feet
B.81 1/4 feet
C.16 Feet
D.15 1/2 feet

1 answer:

34kurt3 years ago

7 0

D. 15.5

40*10.5 = 420

6510/420 = 15.5

You might be interested in

Simplify this expression 9+3x2

Len [333]

9+3x^2

It's technically already in simplest form, except you usually put x first

=3x^2+9

8 0

4 years ago

Find two consecutive positive integers such that the sum of their squares is 421 .

maria [59]

We assume the two numbers are x and (x+1)
so x^2+(x+1)^2=421
x^2+(x^2+2x+1)=421
2x^2+2x-420=0
According to the formula of quadratic
x=14 or-15
cuz we know the two numbers are integers
so x=14
therefore the other number is 15
To make sure that's correct
14^2+15^2=421

Hope that helps you!!

4 0

3 years ago

Fred flips a coin, spins the spinner, and rolls a standard number cube. Find the probability that the coin will show tails, the

Inessa05 [86]

Answer:

The probability that the coin will show tails, the spinner will land on yellow or green (out of yellow, green, blue), and the cube will show a three is $\frac{4}{3}$

Step-by-step explanation:

Given : Fred flips a coin, spins the spinner, and rolls a standard number cube.

To find : The probability that the coin will show tails, the spinner will land on yellow or green (out of yellow, green, blue), and the cube will show a three ?

Solution :

First we find probability one by one,

1) Flips a coin - Head, Tail

Total number of outcome = 2

Favorable outcome (getting a tail) = 1

Probability that the coin will show tails is $P(T)=\frac{1}{2}$

2) Spins the spinner - yellow, green, blue

Total number of outcome = 3

Favorable outcome (land on yellow or green) = 2

Probability that the spinner will land on yellow or green $P(S)=\frac{2}{3}$

3) Rolls a standard number cube - 1,2,3,4,5,6

Total number of outcome = 6

Favorable outcome (show a three) = 1

Probability that the cube will show a three $P(C)=\frac{1}{6}$

The probability that the coin will show tails, the spinner will land on yellow or green (out of yellow, green, blue), and the cube will show a three is

$P=P(T)+P(S)+P(C)$

$P=\frac{1}{2}+\frac{2}{3}+\frac{1}{6}$

$P=\frac{3+4+1}{6}$

$P=\frac{8}{6}$

$P=\frac{4}{3}$

Therefore, The probability that the coin will show tails, the spinner will land on yellow or green (out of yellow, green, blue), and the cube will show a three is $\frac{4}{3}$

5 0

3 years ago

A triangle is enlarged by a factor of 3. The perimeter of the new triangle is 36 feet. What could be the lengths of the sides of

Burka [1]

3 feet 4 feet 5 feet is the answer. 3(3 + 4 + 5)=36

4 0

3 years ago

A 5-gallon jug of cleaning solution contains 6% bleach. How much pure water should be added to it to dilute to 4% bleach?

mihalych1998 [28]

Let's bear in mind that 5 gallons with a solution of 6% bleach, contains some water plus some bleach, how much bleach? well, is just 6% of 5 gallons or namely (6/100) * 5 gallons, or 0.30 gallons.

if we use "x" gallons of water, well pure water has no bleach, so is 0% bleach, and it has a (0/100) * x or 0x gallons of bleach.

the mixture will be say "y" gallons, and is 4% bleach, so (4/100) * y is 0.04y gallons in the mixture of bleach.

$\bf \begin{array}{lcccl}
&\stackrel{gallons}{quantity}&\stackrel{\textit{\% of bleach}}{amount}&\stackrel{\textit{gallons of bleach}}{amount}\\
&------&------&------\\
\textit{pure water}&x&0.00&0x\\
\textit{6\% solution}&5&0.06&0.3\\
-----&------&------&------\\
mixture&y&0.04&0.04y
\end{array}
\\\\\\
\begin{cases}
x+5=\boxed{y}\\
0x+0.3=0.04y\\
---------\\
0.3=0.04\left( \boxed{x+5} \right)
\end{cases}
\\\\\\
0.3=0.04x+0.2\implies 0.1=0.04x\implies \cfrac{0.1}{0.04}=x\implies 2.5=x$

3 0

3 years ago