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2 years ago

In a two-digit number, the tens' digit is 1 less than the units' digit. If the digits are

Mathematics

1 answer:

Tomtit [17]2 years ago

6 0

Answer:

Step-by-step explanation:

Number: AB

A = B-1

BA + AB = 143

10*B + A + 10*A + B = 143

11A + 11B = 143

A + B = 13

(B-1) + B = 13

2B = 14

B = 7

A = 6

The number is 67

check: 6 = 7-1 and 67 + 76 = 143

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3 years ago

The graph of a system of equations will intersect at exactly 1 point?

andrey2020 [161]

Answer:

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3 years ago

A storage tank will have a circular base of radius r and a height of r. The tank can be either cylindrical or hemispherical (ha

Neko [114]

Answer:

Volume: $\frac{2}{3}\pi r^3$

Ratio: $\frac{2}{9}r$

Step-by-step explanation:

First of all, we need to find the volume of the hemispherical tank.

The volume of a sphere is given by:

$V=\frac{4}{3}\pi r^3$

where

r is the radius of the sphere

V is the volume

Here, we have a hemispherical tank: a hemisphere is exactly a sphere cut in a half, so its volume is half that of the sphere:

$V'=\frac{V}{2}=\frac{\frac{4}{3}\pi r^3}{2}=\frac{2}{3}\pi r^3$

Now we want to find the ratio between the volume of the hemisphere and its surface area.

The surface area of a sphere is

$A=4 \pi r^2$

For a hemisphere, the area of the curved part of the surface is therefore half of this value, so $2\pi r^2$ . Moreover, we have to add the surface of the base, which is $\pi r^2$ . So the total surface area of the hemispherical tank is