# Examples for 7th grade (seventh) - page 84

1. Reducing scale I am sizing some landscaping and I measured everything for a 20 to 1 scale. I realized when I was done that it was at 30 to 1. How can I convert what I already have to 30 to 1. (Example, grass area is 22,871.6' at 20 to 1, how do you figure it out to be 30
2. Birthday party For her youngest son's birthday party, mother bought 6 3/4 kg of hotdog and 5 1/3 dozens bread rolls. Hotdogs cost 160 per kilogram and a dozen bread roll costs 25. How much did she spend in all?
3. Down syndrome Down syndrome is one of the serious diseases caused by a gene mutation. Down syndrome occurs in approximately every 550-born child. Express the incidence of Down's syndrome in newborns at per mille.
4. To improper fraction Change mixed number to improper fraction a) 1 2/15 b) -2 15/17
5. Customary length Convert length 65yd 2 ft to ft
6. The lowest The lowest temperature on Thursday was 20°C. The lowest temperature on Saturday was 12°C. What was the difference between the lowest temperatures?
7. Mysterious number The magician thinks the number: "The mysterious number is first divided by minus five, dividing the result by three, multiplying the number by ten, and dividing the resulting number by minus four. This gives result 5. Can you reveal the mysterious number?
8. Pencil cut Veronika cut 10cm pencil. Each turn, the pencil was reduced by 0.2mm. She turned the pencil 100 times. How many centimeters has a pencil now?
9. Unknown number I think the number. I'll reduce it to its one-third. The result is then increased by one-third, and I get the number 12.
10. Difference in temperatures The temperature in the number line show minus 15 degree celsius and 8 degree celsius. What is the different between the temperatures?
11. Melting point The melting point of mercury is -36°F and its boiling point is 672°F. What is the difference between the boiling point and the melting point?
12. A man A man spends 5/9 of his money on rent, and 5/16 of the remainder on electricity. If the final balance remaining is 550 find how much was spent on rent
13. Two angles The triangles ABC and A'B'C 'are similar. In the ABC triangle, the two angles are 25° and 65°. Explain why in the triangle A'B'C 'is the sum of two angles of 90 degrees.
14. Last page Two consecutive sheets dropped out of the book. The sum of the numbers on the sides of the dropped sheets is 154. What is the number of the last page of the dropped sheets?
15. Andre Andre, Thomas, and Ivan split 88 postage stamps in a 2:5:4 ratio. How much did Thomas get?
16. Regrouping Subtract mixed number with regrouping: 11 17/20- 6 19/20
17. Twenty Twenty rabbits are put in 4 cells so that there are different number of rabbits in each cell contains at least 3 rabbits. What is the largest possible number of rabbits in one cell
18. Taxi A taxi ride costs \$3 plus \$2.50 per mile. Write and Graph an equation in two variables that represents the total cost of a taxi ride.
19. Maria Maria has decided to plant grapes in the garden behind her house. His neighbor Ben has grown grapes successfully for a long time and has given Maria advice on how to plant vines. Ben told her to plant them 3 meters apart in rows that are also 3 meters apar
20. Factors 2 A number has 3 identical factors. If 1 of them is 18. Find the number step by step

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