Examples for 8th grade - page 74
- Even / odd numbers
a / Using variable n write two consecutive odd numbers. b / the sum of three consecutive odd numbers is 333. What are this numbers?
- Prism - eq triangle
Calculate the volume and surface of the prism with the base of an equilateral triangle with side a = 4cm and the body height is 6cm.
Peter and Stano lawn grass for 3 hours 12 minutes. How long would it take to Peter if Stano lawn grass himself for 384 minutes.
- Principal and interest
Peter put € 270 principal into bank and at the end of the year on account was € 282. To what annual interest rate that Peter had deposited money in the bank?
Rectangular billboard is 2.5 m long with a diagonal 2.8 m long. Calculate the perimeter and the content area of the billboard.
A one-third of unknown number is equal to five times as great as the difference of the same unknown number and number 28. Determine the unknown number.
- The percentages in practice
If every tenth apple on the tree is rotten it can be expressed by percentages: 10% of the apples on the tree is rotten. Tell percent using the following information: a. in June rained 6 days b, increase worker pay 500 euros to 50 euros c, grabbed 21 fro
- Apples 2
James has 13 apples. It has 30 percent more apples than Sam. How many apples has Sam?
The thickness of a metallic tube is 1cm and its outer radius is 11cm. Find the mass of such 1m long tube, if the density of the metal is 7.5g per cubic cm.
- Barrel 4
Barrel of water weighs 63 kg. After off 75% water, the weight of the barrel with water is 21 kg. How many kg weigh empty barrel and how many kgs water in it?
Grandmother baked cakes. Half of its was poppy, quarter with plum jam and 16 cheesecakes. How many cakes she baked in total?
- Points on circle
In the Cartesian coordinate system with the origin O is a sketched circle k /O; r=2 cm/. Write all the points that lie on a circle k and whose coordinates are integers. Write all the points that lie on the circle I / O; r=5 cm / and whose coordinates are i
Mrs. Violet brewed 15 l of raspberry juice. She poured it into 17 bottles. Some were 3/4 liter and some one liter. How many was bottles of this two types?
- Apples 2
How many apples were originally on the tree, if the first day fell one third, the second day quarter of the rest and on tree remained 45 apples?
For the first week of material collection events are picked up at the school 850 kg of paper and 305 kg of rags which represented 55% of total collection for 14 days. How many kilograms of secondary raw materials were handed over totally?
Joshka had € 15. Mama took him 15%. How many had left?
Write smallest three-digit number, which in division 5 and 7 gives the rest 2.
- Savings and retirement
The older sibling has saved 44% more euros than the youngest, which represents 22 euros. How many euros older brother has saved ?
- Tiles path
A rectangular park measures 24mX18m. A path 2.4m wide is constructed all around it. Find the cost of paving the path with cement tiles of size 60cm X 40cm at the rate of $5.60 per tile ?
- Password dalibor
Kamila wants to change the password daliborZ by a) two consonants exchanged between themselves, b) changes one little vowel to such same great vowel c) makes this two changes. How many opportunities have a choice?