# Percentages - examples - page 21

1. Utopia Island A probability of disease A on the island of Utopia is 40%. A probability of occurrence among the men of this island, which make up 60% of all the population (the rest are women), is 50%. What is the probability of occurrence of A disease among women on Uto
2. Rate or interest At what rate percent will Rs.2000 amount to Rs.2315.25 in 3 years at compound interest?
3. Sale A camera has a listed price of \$751.98 before tax. If the sales tax rate is 9.25%, find the total cost of the camera with sales tax included.
4. Sale discount The product was discounted so that eight products at a new price cost just as five products at an old price. How many percents is the new price lower than the old price?
5. Cube edges If the edge length of the cube increases by 50%, how does the volume of this cube increase?
6. Four numbers The first number is 50% second, the second number is 40% third, the third number is 20% of the fourth. The sum is 396. What are the numbers?
7. Mushrooms Fresh mushrooms contain 88% water, dried 14% water. How many kilograms of fresh mushrooms should be collected to get 3 kg of dried?
8. Mixture How many percentages mixtures do we get by adding 23ml of matter to 89ml of water?
9. Pupils There are 32 pupils in the classroom, and girls are two-thirds more than boys. a) How many percents are more girls than boys? Round the result to a whole percentage. b) How many are boys in the class? c) Find the ratio of boys and girls in the class. Wr
10. Sixty Sixty percent of one-fifteen of the total is equal to thirty. What are two percent of the total?
11. Vinegar mixing We mix 70g water and 50g 8% vinegar. How many percents of the solution of vinegar we produce?
12. Test points If you earned 80% of the possible 40 points, how many points did you miss to get 100%?
13. Profit per kilo The trader sells apples at a profit of 20% per kilogram. Today, he decided to reduce the price of apples by 10%. How much profit does the trader have today?
14. Family 94 boys are born per 100 girls. Determine the probability that there are two boys in a randomly selected family with three children.
15. Tropical, mild and arctic How many percents of the Earth's surface lies in the tropical, mild and arctic range? The border between the ranges is the parallel 23°27 'and 66°33'.
16. Sales off The price has decreased by 20%. How many percents do I have to raise the new price to be the same as before the cut?
17. Borrowing I borrow 25,000 to 6.9% p.a.. I pay 500 per month. How much will I pay and for how long?
18. Acid evaporation How many kilograms of water do we have to evaporate from 100 kg of 32% acid to make it 80% concentration?
19. Clogging How much distilled water must the pharmacist add to 30g of a 30% hydrogen peroxide solution to obtain a 3% solution to clogging?
20. Merchant The merchant lower cost by 10% in December when it was not sold. Again in January lower cost by 20% and now costs 576 €. A. How much the goods stood originally? B, how much cost the goods after the first lowering? C, How many percents totally merchant lo

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