# Examples for 7th grade (seventh) - page 85

1. Erica Erica bought 3 1/2 yards of fabric. If she uses 2/3 of the fabric, how much will she have left?
2. Geometric plan At what scale the building plan if one side of the building is 45m long and 12mm long on a plan?
3. Length subtracting Express in mm: 5 3/10 cm - 2/5 mm
4. Arble bag A marble bag sold by Rachel's Marble Company contains 5 orange marbles for every 6 green marbles. If a bag has 35 orange marbles, how many green marbles does it contain?
5. Babysitting The amount that Susan charges per hour for babysitting are directly proportional to the number of children she is watching. She charges \$4.50 for 3 kids. How much would she charge to babysit 5 kids?
6. Reservoir 3 How many cubic feet of water is stored in the reservoir that has a length of 200 feet, a width of 100 feet, an overflow depth of 32 feet, and a current water level of 24 feet?
7. Delayed clock Michael put a new battery into his watch at midnight. However, they are 5 seconds late each minute. How many hours does the watch show in 24 hours?
8. Pages counting There are pages numbered from 2 to 104 in the book. How many digits have to be printed to number the pages?
9. Comparing and sorting Arrange in descending order this fractions: 2/7, 7/10 & 1/2
10. Land area 2 A land area was divided among the three heirs in the ratio 5:2:4. If the largest share was 20 hectares of land, what is the total area of land? Please show your solution and what kind of proportion is this please
11. Flour Kim needs 3/4 cup of flour to make 12 cookies. How much flour would she need to make 60 cookies?
12. The perimeter 3 The perimeter of a rectangle is 35 cm. The ratio of the length to its width is 3:2. Calculate the dimensions of the rectangle
13. Two vans At 8:30 a. M. , two vans leave at a parking area. They travel in opposite directions: one van travels at 48 km/h and the other at 62 km/h. At what time will the cars be 550 km apart?
14. Allan Allan keeps tropical fish. His aquarium is 4 feet long, 1 foot wide, and 2 feet tall. Each fish needs at least 0.5ft³ of water. What is the maximum number of fish that he can keep in the aquarium? Please show your solution. Please
15. If the 2 If the temperature is 86 degrees in Fahrenheit, what is the same temperature in Celsius?
16. The average The average of one set of 4 numbers is 35. The average of another set of number is 20. The average of the numbers in the two sets is 30. How many numbers are there in the other set?
17. Boats Three-quarters of boats are white, 1/7 are blue and 9 are red. How many boats do we have?
18. A number A number increased by 7.9 is 8.3
19. Temperature change The mean temperature change is -3.2°F per day for five days. What is the total change over the five day period?
20. Sides of triangle Triangle circumference with two identical sides is 117cm. The third side measures 44cm. How many cms do you measure one of the same sides?

Do you have an interesting mathematical example that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.