Math, asked by archanasicalling03, 11 months ago

if 20% of a number is equal to 40 what is the number​

Answers

Answered by banaitvarsha9008
8

Step-by-step explanation:

Solution

30% of 30 is written as

30% × 30 = (30 / 100) × 30 = 900 / 100 = 9

150% of 60 =

Solution

150% of 60 is written as

150% × 60 = (150 / 100) × 60 = (150 × 60) / 100 = 90

1/4 =

4%

1%

0.25%

25%

Solution

We need to change the fraction 1 / 4 into a fraction with denominator 100 which is a percent

1 / 4 = (1 × 25) / (4 × 25) = 25 / 100 = 25%

0.05 =

50%

500%

5%

0.5%

Solution

We need to change the decimal number 0.05 into a fraction with denominator 100 which is a percent

0.05 = 0.05 / 1 = (0.05 × 100) / (1 × 100) = 5 / 100 = 5%

If 100% of a number is 15, what is 50% of the number?

Solution

Let n be the number

100% of a number is 15 is written as: 100% × n = 15

100% = 100 / 100 = 1

Hence

100% × n = n = 15

We now need to find 50% of the number

50% of 15 = (50 / 100) × 15 = 750 / 100 = 7.5

NOTE that the above problem could be solved by noting that 50% of something is half of 100% of the same thing. Hence if 100% of something is 15 then 50% of the same thing is haflf of 15 / 2 = 7.5

If 10% of a number is 7, what is 80% of the number?

Solution

Note that 80% of something is 8 times 10% of the same thing. Hence if 10% of a number is 7 then 80% of the same number is given by

8 × 7 = 56

Which is the greatest?

90% of 10

6% of 1000

5% of 1400

3% of 2500

Solution

Express as fractions with same denominator 100 and then compare

90% of 10 = (90 / 100) × 10 = 900 / 100

6% of 1000 = (6 / 100) × 1000 = 6000 / 100

5% of 1400 = (5 /100) × 1400 = 7000 / 100

3% of 2500 = (3 / 100) × 2500 = 7500 / 100

The largest fraction is 7500 / 100 which correspond to 3% of 2500. Hence 3% of 2500 is the largest.

The original price of a toy was $15. If the price is reduced by 20%, what is the new price of the toy?

Solution

20% of price is

20% × 15 = $3

The original price was $15 and was reduced by 20% or $3. Hence the new price after reduction is

15 - 3 = $12

George bought a car at $5000 and sold it at $5500. What benefit, in percent, did he make?

Solution

The benefit in dollars is

$5500 - $5000 = $500

Express $500 as a percent of $5000 as follows

500 / 5000 = 5 / 50 = 10 / 100 = 10%

If 20% of n is equal to 40, what is n?

Solution

"20% of n is equal to 40" is written as

20% × n = 40

(20 / 100) × n = 40

Rewrite the above with fraction on the right side with denominator equal to 100

20 n / 100 = 40 / 1 = 4000 / 100

Since the two fractions have same denominator and are equal, their numerator must be equal. Hence

20 n = 4000 which means that n = 200.

200

2000

800

80

The price of a T-shirt was $20. It was first increased by 20%. They did not sell well the shop owner decreased the price by 20%. What is the new price of the T-shirt?

$20

$22

$21

$19.20

What percent of 1 hour is 15 minutes?

50%

15%

75%

25%

Answers to the Above Questions

C

D

D

C

A

B

D

A

B

A

D

D

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Answered by amancharlie3172
1

Answer:

Answer is 200

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