# Examples for 7th grade (seventh) - page 34

- Fire tank

How deep is the fire tank with the dimensions of the bottom 7m and 12m, when filled with 420 m^{3}of water? - Two tributaries

Two tributaries of the pool fill it in 10 hours. One of the tributaries would fill 15 hours. How long would fill the first tributary? - Saw

Imagine that the saw blade with diameter 40 cm has one tooth colored with a different color. How long is path describing by the tip of the tooth after 15 minutes, if the blade is rotated 13365 times? - Angles

The outer angle of the triangle ABC at the vertex A is 114°12'. The outer angle at the vertex B is 139°18'. What size is the internal angle at the vertex C? - Ratio of perimeters

Rectangle ABCD has dimensions 3 cm and 4 cm, KLMN rectangle has dimensions 4 cm and 12 cm. Calculate the ratio of the perimeter ABCD and perimeter KLMN. - Train expres

At 8.00 strarted from Bratislava to Poprad express Tatry. Cities are distant 340 kilometers. At the same time started from Poprad express Danube to Bratislava. Express Tatry's average speed is 80 km/h, Danube 90 km/h. At what distance from Poprad trains w - Area of the cone

Calculate the surface area of the cone, you know the base diameter 25 cm and a height 40 cm. - Distance runner

Distance runner already climbed three fifths of the total route. Thus passed 90 km. How many km he have to stop? How long is his route? - Determine the number

Determine the number x that ?. - Rectangles - sides

One side of the rectangle is 10 cm longer than second. Shortens longer side by 6 cm and extend shorter by 14 cm increases the area of the rectangle by 130 cm^{2}. What are the dimensions of the original rectangle? - Rectangle

The width of the rectangle is 65% of its length. Perimeter of the rectangle is 132 cm. Determine the dimensions of the rectangle. - Diplomas

Suzanne helped write out diplomas. Issuance its first took 3 minutes, each next 2.3 minutes. How much time it will take to write out n=16 diplomas (including the first), write out this pace? - The store

The store received the same number of cans of peas and corn. The first day sold 10 cans of peas and 166 cans ofcorn so that left 5 times more peas than corn cans. How many cans of each kind were in the store? - Area of RT 2

Calculate the area of right triangle whose legs have a length 5.8 cm and 5.8 cm. - Motor oil

30 liters of oil cost 28.80 Euros. How much cost a liter? - Two numbers

The sum of two numbers is 1. Identify this two numbers if you know that the half of first is equal to the third of second number. - Nectar

Nectar collected by bees contains 70% water. From the nectar of the some process produces honey which contains 19% water. How many kg of nectar bees need to collect to make 1 kg of honey? - Cottages

The summer camp is 41 cottages. Rooms are for three and for four in them. How many of the 140 campers lives of three? - Is right triangle

One angle of the triangle is 36° and the remaining two are in the ratio 3:5. Determine whether triangle is a rectangular triangle. - 9-gon

Sum of interiol angles of 9-gon is:

- «
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- »

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