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2 years ago

The mean age of a group of students is 16. John joins the group and the mean age changes to 18. How old is john ?

Mathematics

1 answer:

schepotkina [342]2 years ago

5 0

Answer:

John is 20 years old.

Step-by-step explanation:

Given the second mean is 18, it is equal to the first mean age plus John's unknown age. The sum is also divided by 2 because there are 2 values in the sum (1. John's age and 2. the mean, 16 yrs old).

Set up an equation: $\frac{x+16}{2}=18$

multiply both sides by 2: $x+16=36$

simplify: $x=20$

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Alchen [17]

Answer:

Step-by-step explanation:

B) the stone hits the water within the first 2 seconds. Because the stone drops at the speed of 88 feet/second, and 88 x 2 is 176. but the bridge is only 135 feet tall.

so,

88 feet/second

176 feet/2 seconds

135 feet means that it reached the river within 2 seconds. it reached the river in 1.545 seconds

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2 years ago

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6. The table shows the equations Ms. Valez discussed in math class today.

k0ka [10]

Answer:

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Step-by-step explanation:

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4 years ago

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A piece of cloth was 30 feet long. how long is this cloth in yards? one yard = 3 feet

Alinara [238K]

Answer:

10 yards

Step-by-step explanation:

Every 1 yard is 3 feet, the cloth is 30 feet
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The cloth is 10 yards.

Hope this helps!

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2 years ago

Given: circle k(O), m∠P=95°, m∠J=110°, m∠LK=125°<br> Find: m∠PJ

IRINA_888 [86]

Answer:

The measure of the arc PJ is $75\°$

Step-by-step explanation:

step 1

Find the measure of angle L

we know that

In a inscribed quadrilateral opposite angles are supplementary

$m$

we have

$m$

substitute

$m$

step 2

Find the measure of arc KJ

we know that

The inscribed angle measures half that of the arc comprising

$m$

substitute the values

$95\°=\frac{1}{2}(125\°+arc\ KJ)$

$190\°=(125\°+arc\ KJ)$

$arc\ KJ=190\°-125\°=65\°$

step 3

Find the measure of arc PJ

we know that

The inscribed angle measures half that of the arc comprising

$m$

substitute the values

$70\°=\frac{1}{2}(65\°+arc\ PJ)$

$140\°=(65\°+arc\ PJ)$

$arc\ PJ=140\°-65\°=75\°$

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3 years ago

leo knows that each time a digit moves one place to the left in a whole number the value of the digit is 10 times as much. descr

Serga [27]

Answer:

Leo is true for any numbers (including decimal numbers)

Step-by-step explanation:

* Lets explain how to solve the problem

- In number 256

# 6 is the unit digit (one digit)

# 5 is the ten digit (10 digit)

# 2 is the hundred digit (100 digit)

- If we change the number to 2563

# 6 digit is moved 1 place to the left now its place changed from unit

digit to ten digit (from 1 to 10) that means 6 in the second number

is 10 times the 6 in the first number

# 5 digit is moved 1 place to the left now its place changed from ten

digit to hundred digit (from 10 to 100) that means 5 in the second

number is 10 times the 5 in the first number

# 2 digit is moved 1 place to the left now its place changed from

hundred digit to thousand digit (from 100 to 1000) that means 2

in the second number is 10 times the 2 in the first number

- In number 2.345

# 2 is the unit digit (one digit)

# 3 is the tenth digit (1/10 digit)

# 4 is the hundredth digit (1/100 digit)

# 5 is the thousandth digit (1/1000 digit)

- If we change the number to 23.45

# 3 digit is moved 1 place to the left now its place changed from tenth

digit to unit digit (from 1/10 to 1) that means 3 in the second number

is 10 times the 3 in the first number

# 4 digit is moved 1 place to the left now its place changed from

hundredth digit to tenth digit (from 1/100 to 1/10) that means 4 in the

second number is 10 times the 5 in the first number

# 5 digit is moved 1 place to the left now its place changed from

thousandth digit to hundredth digit (from 1/1000 to 1/100) that means

5 in the second number is 10 times the 5 in the first number

∴ Leo is true for any numbers (including decimal numbers)

3 0

3 years ago