I NEEDZ HELPZZZZZZZZ!!!!<br><br><br>btw i didnt mean to click d)20..

nadya68 [22]

Answer:

75% of 352 children are boys

Step-by-step explanation:

If 5/6 of the people participaticipants to a concert are adults then 1 out of 6 prople are children so we may reach a number of 2112:6=352 children

if 25% of the children are girls then 75% are boys

88×3=264 boys

7 0

3 years ago

Suppose that a large mixing tank initially holds 500 gallons of water in which 50 pounds of salt have been dissolved. Another br

Lina20 [59]

Answer:

The differential equation for the amount of salt A(t) in the tank at a time t > 0 is $\frac{dA}{dt}=12 - \frac{2A(t)}{500+t}$ .

Step-by-step explanation:

We are given that a large mixing tank initially holds 500 gallons of water in which 50 pounds of salt have been dissolved. Another brine solution is pumped into the tank at a rate of 3 gal/min, and when the solution is well stirred, it is then pumped out at a slower rate of 2 gal/min.

The concentration of the solution entering is 4 lb/gal.

Firstly, as we know that the rate of change in the amount of salt with respect to time is given by;

$\frac{dA}{dt}= \text{R}_i_n - \text{R}_o_u_t$

where, $\text{R}_i_n$ = concentration of salt in the inflow $\times$ input rate of brine solution

and $\text{R}_o_u_t$ = concentration of salt in the outflow $\times$ outflow rate of brine solution

So, $\text{R}_i_n$ = 4 lb/gal $\times$ 3 gal/min = 12 lb/gal

Now, the rate of accumulation = Rate of input of solution - Rate of output of solution

= 3 gal/min - 2 gal/min

= 1 gal/min.

It is stated that a large mixing tank initially holds 500 gallons of water, so after t minutes it will hold (500 + t) gallons in the tank.

So, $\text{R}_o_u_t$ = concentration of salt in the outflow $\times$ outflow rate of brine solution

= $\frac{A(t)}{500+t} \text{ lb/gal } \times 2 \text{ gal/min}$ = $\frac{2A(t)}{500+t} \text{ lb/min }$

Now, the differential equation for the amount of salt A(t) in the tank at a time t > 0 is given by;

= $\frac{dA}{dt}=12\text{ lb/min } - \frac{2A(t)}{500+t} \text{ lb/min }$

or $\frac{dA}{dt}=12 - \frac{2A(t)}{500+t}$ .

4 0

3 years ago

In Marta's class, the ratio of students who ate tacos for lunch to the students who ate burritos was 12:18.

boyakko [2]

Answer:

20 30

Step-by-step explanation:

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3 0

3 years ago

Plzzzzz hellllp meeeee plz

iren [92.7K]

Answer:

(7, 5)

Step-by-step explanation:

When reflecting over the x-axis, the only position that moves is the y-coordinate as it is going above the axis it was previously below. Since point F's original position was (7, -5) it is 5 spaces away from the x-axis. We move 5 places up to be even with the x-axis, then move up another 5 places to reflect the point to get F'.

Hope this Helps!

5 0

3 years ago

Read 2 more answers

What is the best first step in solving the equation 3x2 + 8x = -5?

Rashid [163]

I would assume it would be dividing both sides by three although if someone were to actually solve this I would say multiply 2 and 3 together first.

Hope this helps :)

5 0

3 years ago

I NEEDZ HELPZZZZZZZZ!!!!btw i didnt mean to click d)20..