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Andreyy89
4 years ago
8

Kevin and Randy Muise have a jar containing 70 coins, all of which are either quarters or nickels. The total value of the coins

in the jar is $7.50. How many of each type of coin do they have.​
Mathematics
1 answer:
Nikitich [7]4 years ago
6 0

Answer:

50 nickels, 20 quarters.

Step-by-step explanation:

System of equations (q = # of quarters, n = # of nickels):

<em>q + n = 70, 0.25q + 0.05n = 7.50</em>

the first equation can be changed to q = 70 - n, so we are able to <em>substitute q with 70 - n</em>.

So, it will look like <em>0.25*70 - 0.25n + 0.05n = 7.50</em>. This can be simplified to <em>0.2n = 10</em>, which means that n = 50.

Knowing that we can solve <em>q + 50 = 70</em>, which means that q = 20.

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El MCM de dos números es 200 y su MCD es 4. Si uno de ellos es 8, ¿cuál es el otro número?
avanturin [10]

Answer: The other number is 100.

Step-by-step explanation:

The least common multiple (LCM) of two numbers is 200

The greatest common denominator (GCD) is 4.

One of the numbers is 8, which is the other number?

Ok:

First, we can write 8 as: 2*2*2 = 2^3 = 2*4

Now, the minimal common denominator can be any number that is written in the form

x = 4*a*b..

where a, b etc are prime numbers.

We also know that

LCD(a,b) = a*b/GCD(a,b)

LCD(8,x) = 8*x/GCD(8, x)

200 = 8*x/4

x = 200*4/8 = 100

the other number is 100.

4 0
3 years ago
The student council had a canned food drive. they collected a total of 63 cans on wednesday. this is 21% of the total. how many
Mama L [17]
The total is 300 cans. And 46percent of the total is 138. Therefore 138canned food was collected on Thursday.
4 0
4 years ago
A cone has a radius of 5 ft and a height of 15 ft. It is empty and is being filled with water at a constant rate of 15 15 ft 3 f
kvasek [131]

Answer:

\frac{dr}{dt}=0.11062ft/sec

Step-by-step explanation:

From the question we are told that:

Radius r=5ft

Height H=15ft

Rate R=15ft/3sec =5ft/s

Surface Radius R_{surf}=2.2ft

Generally the equation for Volume is mathematically given by

 V=\frac{1}{3}\pi*r^2h

Since radius to height ratio gives

 \frac{r}{h}=\frac{5}{15}

 \frac{r}{h}=\frac{1}{3}

 h=3r

Therefore

 V=\frac{1}{3}\pi*r^2(3r)

 V=\pi r^3

Generally the equation for Change of Volume is mathematically given by

 \frac{dv}{dt}=\pi \frac{d}{dt}(r^3)

 \frac{dv}{dt}=\pi 3*r^2 \frac{dr}{dt}

 \frac{dv}{dt}=\pi 3*(2.2)^2 \frac{dr}{dt}

 \frac{dr}{dt}=\frac{5}{45.62}

 \frac{dr}{dt}=0.11062ft/sec

3 0
3 years ago
Help with this please?....:)<br>​
marusya05 [52]

Answer:

200. 96 cm^2

Step-by-step explanation:

If the area of a circle is \pir^{2}

\pi = 3.14,

radius = 8 cm (r = diameter/2   ----> r = 16/2)

= \pir^{2}

= 3.14 (8^{2})\\=  200. 96 cm^{2}

7 0
3 years ago
Barbara charges $3.50, plus $2.25 for each hour she babysits. If Barbara charges $21.50, how many hours does she babysit?
MAVERICK [17]

Answer:

8 hours

Step-by-step explanation:

The equation is 2.25X + 3.50 = 21.50

X represents the unknown amount of hours she worked. 2.25 is the cost per hour. 3.50 is the fee she charges for every gig. That fee only happens once a gig so naturally it wasn't the number x was placed with.

2.25X + 3.50 = 21.50

2.25X + 3.50 - 3.50 = 21.50 - 3.50

2.25X = 18

<u>2.25X</u> = <u>1</u><u>8</u>

2.25 2.25

X = 8

8 0
3 years ago
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