Advertisements
Advertisements
प्रश्न
If A is increased by 20%, it equals B. If B is decreased by 50%, it equals C. Then ______ % of A is equal to C.
Advertisements
उत्तर
If A is increased by 20%, it equals B. If B is decreased by 50%, it equals C. Then 60 % of A is equal to C.
Explanation:
Given, If A is increased by 20%, then it is equal to B.
∴ A + 20% of A = B
⇒ `A(1 + 20/100) = B`
⇒ `120/100 A = B`
⇒ `B = 6/5 A` ...(i)
If B is decreased by 50%, then it is equal to C.
∴ B – 50% of B = C
⇒ `B(1 - 50/100) = C`
⇒ `B xx 50/100 = C`
⇒ `1/2 B = C`
⇒ B = 2C ...(ii)
On comparing equations (i) and (ii), we get
`6/5 A = 2C`
⇒ `A/C = 10/6`
⇒ `C = 6/10`
⇒ `C = 3/5 A`
∴ In percentage, `C/A xx 100 = (3/5 A)/A xx 100%`
= `3/5 xx 100%`
= 60%
Hence, 60% of A is equal to C.
APPEARS IN
संबंधित प्रश्न
On Sunday 845 people went to the Zoo. On Monday only 169 people went. What is the per cent decrease in the people visiting the zoo on Monday?
Kayal scored 225 marks out of 500 in revision test 1 and 265 out of 500 marks in revision test 2. Find the percentage of increase in her score
Radhika bought a car for Rs 2,50,000. Next year its price decreased by 10% and further next year it decreased by 12%. In the two years overall decrease per cent in the price of the car is ______.
Three times a number is 200% increase in the number, then one-third of the same number is 200% decrease in the number.
Number of students appearing for class X CBSE examination increases from 91,422 in 1999 – 2000 to 11,6054 in 2008 – 09. Increase in the number of students appeared is approximately 27%.
What is the percentage increase or decrease in the number of seats won by A, B, C and D in the general elections of 2009 as compared to the results of 2004?
| Political party | Number of seats won in 2004 |
Number of seats won in 2009 |
| A | 206 | 145 |
| B | 116 | 138 |
| C | 4 | 24 |
| D | 11 | 12 |
The food labels given below give information about 2 types of soup: cream of tomato and sweet corn. Use these labels to answer the given questions. (All the servings are based on a 2000 calorie diet.)
| Sweet Corn | Cream of Tomato | ||
| Nutrition Facts | Nutrition Facts | ||
| Serving Size 1 cup (240ml) | Serving Size 1 cup (240ml) | ||
| About 2 serving per Container | About 2 serving per Container | ||
| Amount Per Serving | Amount Per Serving | ||
| Calories 90 | Calories from Fat 9 | Calories 100 | Calories from Fat 20 |
| % Daily Value* | % Daily Value* | ||
| Total Fat 2g | 2% | Total Fat 2g | 3% |
| Saturated Fat-0g | 0% | Saturated Fat-1.5g | 6% |
| Cholesterol 0mg | 0% | Cholesterol 10mg | 3% |
| Sodium 540mg | 22% | Sodium 690mg | 29% |
| Total Carbohydrate 17g | 6% | Total Carbohydrate 17g | 6% |
| Dietary Fibre 3 gram | 14% | Dietary Fibre 4 gram | 18% |
| Sugar 5g | Sugar 11g | ||
| Protein 3g | Protein 2g | ||
| Vitamin A 30% | Vitamin C 10% | Vitamin A 20% | Vitamin C 20% |
| Calcium 2% | Iron 6% | Calcium 0% | Iron 8% |
| *Per cent Daily Values are based on a 2,000 calorie diet. |
*Per cent Daily Values are based on a 2,000 calorie diet. |
||
Find the increase per cent of sugar consumed if cream of tomato soup is chosen over sweet corn soup.
For an amount, explain why, a 20% increase followed by a 20% decrease is less than the original amount.
Sunscreens block harmful ultraviolet (UV) rays produced by the sun. Each sunscreen has a Sun Protection Factor (SPF) that tells you how many minutes you can stay in the sun before you receive one minute of burning UV rays. For example, if you apply sunscreen with SPF 15, you get 1 minute of UV rays for every 15 minutes you stay in the sun.
Suppose a sunscreen allows 25% of the sun’s UV rays.
- What fraction of UV rays does this sunscreen block? Give your answer in lowest terms.
- Use your answer from Part (a) to calculate this sunscreen’s SPF. Explain how you found your answer.
