Question

18 is what percent of 40?
45 is 15% of what number
16% of what number is 20
what is 57% of 240

Answer 1

@mathstudent55

Answer 2

I think the first one is 45%

Answer 3

Let's deal with
"18 is what percent of 40?"
first

Answer 4

do you know the is over of method?

Answer 5

Percent is a ratio.
The entire amount is 100%
That is 45.
You want to know what percent is 18 out of 45.
Set up a proportion:

\(\dfrac{18}{45} = \dfrac{x}{100} \)

Answer 6

cross multiply

Answer 7

18 x 100 is?

Answer 8

Now you can solve the proportion by cross multipying:

\(45x = 18 \cdot 100\)

\(45x = 1800\)

x = 40

Answer: 40%

Answer 9

no 40

Answer 10

not 45

Answer 11

Wait, I just realize I used 45 instead of 40.
Let me do it again.

Answer 12

so write this down: 18/40 = x/100

Answer 13

Percent is a ratio.
The entire amount is 100%; that is 40.
You want to know what percent is 18 out of 40.
Set up a proportion:

\(\dfrac{18}{40} = \dfrac{x}{100} \)

Answer 14

It equals 45%

Answer 15

40x = 18*100
40x = 1800
x = 45
Answer: 45%
@mjperez18 You were correct.

Answer 16

what is 18 x 100

Answer 17

Ready for the second one?

Answer 18

Okay on to the next one

Answer 19

45 is 15% of what number

Answer 20

the next one is a little bit different but still can use a proportion

Answer 21

45 is 15% of what number

Answer 22

Now 45 is the part, and is also15%.
The entire number is x, unknown, and is also 100%.

Answer 23

45 = 15
x = 100

Answer 24

okay

Answer 25

now cross multiply

Answer 26

45 x 100 =?

Answer 27

We set up a new proportion.

\(\dfrac{45}{x} = \dfrac{15}{100} \)

Answer 28

3? or something to do with the number 3

Answer 29

lets just start with 45 x 100

Answer 30

300

Answer 31

45 x 100 = 4500

Answer 32

Again, cross multiply and solve for x.

15x = 45 * 100
15x = 4500
x = 300

Answer 33

15 times x = 15x

Answer 34

Correct. Answer is 300.

Answer 35

Correct

Answer 36

okay 16%of what number is 20

Answer 37

@mathstudent55

Answer 38

The third problem is just like the second one.

Answer 39

okay so 20/x 16/100

Answer 40

remember this ( is/ of = x/100

Answer 41

16% of what number is 20
The unknown is the entire number, or 100%.
The known is that 15% is the part and is 20

Answer 42

\(\dfrac{20}{x} = \dfrac{16}{100} \)

Answer 43

16x = 20 * 100
16x = 2000
x = 125

Answer 44

125?

Answer 45

@mjperez18
Your proportion and answer are correct.

Answer 46

and the next is like the other 2

Answer 47

Last one:
"what is 57% of 240"
This problem is different from all other three above, but it's the easiest percent problem there is.

Answer 48

ok

Answer 49

To find a percent of a number, just multiply the percent (written as a decimal) by the number.
57% is the same as 0.57
57% of 24 is the same as
0.57 * 240
All you need to do is that simple multiplication.

Answer 50

^i meant 240 above not 24.

Answer 51

13.68

Answer 52

percent

Answer 53

Correct.
You did great!

Answer 54

Do you still want to work on the problem of turning $750 into $1000 in 8 years, and how much the simple interest rate must be?

Answer 55

yes please

Answer 56

Ok. Can you please start a new post with just that question. I'll look for it, and I'll go there and will help you.

Answer 57

I thought it was 950

Answer 58

950?
The question is asking for an interest rate in percent.

Answer 59

well I have limited time so can we just complete the question here