# Examples for 9th grade - page 7

- Octahedron - sum

On each wall of a regular octahedron is written one of the numbers 1, 2, 3, 4, 5, 6, 7 and 8, wherein on different sides are different numbers. For each wall John make the sum of the numbers written of three adjacent walls. Thus got eight sums, which also. - Three digits number

How many are three-digit integers such that in they no digit repeats? - Divisors

The sum of all divisors unknown odd number is 1482. Determine sum of all divisors of number which is twice of unknown numbers. - Barrel of oil

Barrel of oil weighs 282 kg. When it mold 56% oil, weighed 138 kg. What is the mass of the empty barrel? - Lines

In how many points will intersect 11 different lines, where no two are parallel? - Root

Use law of square roots roots: ? - Dice

How many times must throw the dice, the probability of throwing at least one three was greater than 90%? - Lock

Combination lock will open when the right choice of 5 numbers (from 1 to 12 inclusive) is selected. A. How many different lock combinations are possible? B. Is he combination lock named appropriately? - Machine

Price of the new machine is € 56000. Every year is depreciated 16% of residual value. What will be the value of the machine after 5 years? - Store

One meter of the textile were discounted by 2.4 USD. Now 6 m of textile cost as before 3 m. Calculate the old and new price of 1 m of the textile. - Morse alphabet

Calculate how many words of Morse code to create compiling commas and dots in the words of one to five characters. - Shadow and light

Nine meters height poplar tree has a shadow 16.2 meters long. How long shadow have at the same time Joe if he is 1,4m tall? - Basketball

Peter and Franta threw to the basket. Each had 20 attempts. Peter scored thirteen and twelve Franta. Give them success in percentage. - Salary

Clerk got to pay 1200 Euros in banknotes of 50 and 200 Eur. Total got 9 banknotes. How many was which? - Party

At party overyone clink with everyone. Together, they clink 406 times. How many people were at the party? - Tanker

An oil tanker can be emptied by the first pump in 4.4 hours. Second pump can empty an tanker in 7.8 hours. If the first pump started at 8:00 and second 1.4 hour later, at what time will the tanker be empty? - Circles

Three circles of radius 71 cm 76 cm and 22 cm is mutually tangent. What is the perimeter of the triangle whose vertices are centers of the circles? - Two typists

There are two typists who are rewriting the material 705 pages. First can it handle rewrite yourself for 24 days; the second 12 days. First typist wrote material yourself 4 days rest rewrites yourself second typist. How many days will it take rewriting alt - Server

Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%. - Road - permille

5 km long road begins at an altitude 500 meters above sea level and ends at a altitude 521 ASL. How many permille road rises?

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