The pie chart below shows the number of books read each year. If the total number of people surveyed is 8000,

Jan's age is 3 years less than twice tritt's age. The sum of their ages is 30. Find their ages.

Mashutka [201]

J + t = 30
j = 2t - 3

2t - 3 + t = 30
3t - 3 = 30
3t = 30 + 3
3t = 33
t = 33/3
t = 11 <=== tritt's age is 11

j = 2t - 3
j = 2(11) - 3
j = 22 - 3
j = 19 <== jan's age is 19

6 0

2 years ago

Read 2 more answers

Describe different ways in which a plane might intersect the cylinder and the cross section that results?

lutik1710 [3]

Answer : If it is perpendicular to the axis, then a circle. If it is at an angle to the axis, then an ellipse. If it is parallel to the axis, then two parallel lines. Those are the only 3 cases that I can think of.

Hope this helps.

6 0

3 years ago

Write one digit on each side of 36 to make a four-digit multiple of 36. How many different solutions does this problem have?

vaieri [72.5K]

9514 1404 393

Answer:

3 solutions: 1368, 5364, 9360

Step-by-step explanation:

In order to be divisible by 36, the number must be divisible by 9 and by 4. The number will be divisible by 9 if the sum of its digits is divisible by 9. 36 already has a digit sum of 9, so the two added digits must sum to 9.

The number will be divisible by 4 if the least-significant digit is a multiple of 4. That is, it must be 0, 4, or 8. Then the corresponding most-significant digits must be 9, 5, or 1.

The three solutions are ...

1368 = 38 · 36

5364 = 149 · 36

9360 = 260 · 36

6 0

2 years ago

What is the numerical solution to the equation five less than three times a number equals four more than eight times rhetorical

Romashka-Z-Leto [24]

Answer:

3n-5=8n+4

Step-by-step explanation:

3 0

3 years ago

Let S be the solid beneath z = 12xy^2 and above z = 0, over the rectangle [0, 1] × [0, 1]. Find the value of m > 1 so that th

jonny [76]

Answer:

The answer is $\sqrt{\frac{6}{5}}$

Step-by-step explanation:

To calculate the volumen of the solid we solve the next double integral:

$\int\limits^1_0\int\limits^1_0 {12xy^{2} } \, dxdy$

Solving:

$\int\limits^1_0 {12x} \, dx \int\limits^1_0 {y^{2} } \, dy$

$[6x^{2} ]{{1} \atop {0}} \right. * [\frac{y^{3}}{3}]{{1} \atop {0}} \right.$

Replacing the limits:

$6*\frac{1}{3} =2$

The plane y=mx divides this volume in two equal parts. So volume of one part is 1.

Since m > 1, hence mx ≤ y ≤ 1, 0 ≤ x ≤ $\frac{1}{m}$

Solving the double integral with these new limits we have:

$\int\limits^\frac{1}{m} _0\int\limits^{1}_{mx} {12xy^{2} } \, dxdy$

This part is a little bit tricky so let's solve the integral first for dy:

$\int\limits^\frac{1}{m}_0 [{12x \frac{y^{3}}{3}}]{{1} \atop {mx}} \right.\, dx =\int\limits^\frac{1}{m}_0 [{4x y^{3 }]{{1} \atop {mx}} \right.\, dx$

Replacing the limits:

$\int\limits^\frac{1}{m}_0 {4x(1-(mx)^{3} )\, dx =\int\limits^\frac{1}{m}_0 {4x-4x(m^{3} x^{3} )\, dx =\int\limits^\frac{1}{m}_0 ({4x-4m^{3} x^{4}) \, dx$

Solving now for dx:

$[{\frac{4x^{2}}{2} -\frac{4m^{3} x^{5}}{5} ]{{\frac{1}{m} } \atop {0}} \right. = [{2x^{2} -\frac{4m^{3} x^{5}}{5} ]{{\frac{1}{m} } \atop {0}} \right.$

Replacing the limits:

$\frac{2}{m^{2} }-\frac{4m^{3}\frac{1}{m^{5}}}{5} =\frac{2}{m^{2} }-\frac{4\frac{1}{m^{2}}}{5} \\ \frac{2}{m^{2} }-\frac{4}{5m^{2} }=\frac{10m^{2}-4m^{2} }{5m^{4}} \\ \frac{6m^{2} }{5m^{4}} =\frac{6}{5m^{2}}$

As I mentioned before, this volume is equal to 1, hence:

$\frac{6}{5m^{2}}=1\\m^{2} =\frac{6}{5} \\m=\sqrt{\frac{6}{5} }$

3 0

2 years ago