Practicas de matemáticas

1) SEVENTH GRADE
Three ducks and two ducklings weigh 32 kg. Four ducks and three ducklings weigh 44kg. All ducks weigh the same and all ducklings weigh the same. What is the weight of two ducks and one duckling?
Need A Hint?
Answer

2)
It takes one man one day to dig a 2m x 2m x 2m hole. How long does it take 3 men working at the same rate to dig a 4m x 4m x 4m hole?
Need A Hint?Answer

3)
A farmer grows 252 kilograms of apples. He sells them to a grocer who divides them into 5 kilogram and 2 kilogram bags. If the grocer uses the same number of 5 kg bags as 2kg bags, then how many bags did he use in all?
Need A Hint?
Answer

4)
A 800 seat multiplex is divided into 3 theatres. There are 270 seats in Theatre 1, and there are 150 more seats in Theatre 2 than inTheatre 3. How many seats are in Theatre 2?
Need A Hint?
Answer

5)
In 1969 the price of 5 kilograms of flour was $0.75. In 1970 the price was increased 15 percent. In 1971, the 1970 price was decreased by 5 percent. What was the price of 5 kilograms of flour in 1971?
Need A Hint?
Answer

6)
A rectangular sheet of wood has four small squares removed. It is then cut to make a box thatis 5cm by 4cm with a volume of 60cm3. (Four pieces of size A4 are removed.)

Find the original area of the sheet of wood.
Need A Hint?
Answer

7)
Mary has $50.00. She goes to the mall and buys lipstick and then she buys shampoo, which is half the price of the lipstick. She then spends half of what she has left on a purse, leaving her with $15.00.
How much did the shampoo cost?
Howmuch did the lipstick cost?
Need A Hint?
Answer

8)
Stephanie had $40.00 savings. Her mother gave her another $30.00 and her grandmother gave her $10.00 to buy a pair of cleats. The pair of cleats Stephanie wants costs $54.99. If Stephanie buys the cleats at a no TAX sale, write an equation using a variable to describe the amount of money that Stephanie will have to contribute from hersavings.
Solve for the variable.
Need A Hint?
Answer

9)
Air is pumped into a vacuum sealed picture below room at a rate of 2 litres per minute. How many seconds does it take to fill the room with air? Use the information given to find the volume of the room.

     a = 3dm   1 mL = 1 cm3
     b = 3dm   1000 mL = 1L
     c = 4dm   1000 cm2 =1 dm = 1L
     d = 5dm
     e = (3a - 1)dm
     f = (1/2b)dm
     g = (3/8a + 3/8b)dm
Need A Hint?
Answer

10)
Given a rectangular prism...

if the sides of the rectangle A have the same ratio to each other as the sides of rectangle B, then what is
* (a) The surface area of the prism?
* (b) The volume of theprism?
Need A Hint?
Answer

11)
The trails in a park resemble the following diagram. Find the total length of the trails, given that all the circles have the same area and circle 2 is tangent to the midpoint of L.

     r = 10m
Need A Hint?
Answer

12)
The rent-a-stall horse barn has stalls for 1000 horses. Forty percent of the stalls are for ponies. On Tuesday,there were 200 ponies and a bunch of quarter horses at the horse barn. The horse barn was 75 percent full.
How many quarter horses were in the stalls?
Need A Hint?
Answer

13)
A rectangular chalk board is 3 times as long as it is wide. If it were 3 metres shorter and 3 metres wider, it would be square. What are the dimensions of the chalk board?
Need A Hint?
Answer

14)
Threepeople share a car for a period of one year and the mean number of kilometers travelled by each person is 152 per month. How many kilometers will be travelled in one year?
Need A Hint?
Answer

15)
A car dealer claims that by buying a new car Mike will pay 1/5 less for gas then he pays for the car he currently drives. If the car Mike currently drives costs 1/6 less to gas up than Dave's car,...