# Examples for 8th grade - page 6

- Number ratio

Calculate two positive numbers that its ratio is 4:4 and sum was 184. - Square diagonal

Calculate the length of diagonal of the square with side a = 23 cm. - Z9-I-4

Kate thought a five-digit integer. She wrote the sum of this number and its half at the first line to the workbook. On the second line wrote a total of this number and its one fifth. On the third row she wrote a sum of this number and its one nines. Fi - Invitations

For every 5 minutes writes Dana 10 invitations, while Anna 14 invitations. How long will write together 120 invitations? - Permill

How many permill is 1931 from 166456? - Compare II

Which of the numbers 15^{8}, 8^{15}is greater? - Tunnels

Mice had built an underground house consisting of chambers and tunnels: • each tunnel leading from the chamber to the chamber (none is blind) • from each chamber lead just three tunnels into three distinct chambers, • from each chamber mice can get to any - Area codes

How many 6 digit area codes are possible if the first number can't be zero? - Madams

During the spring cleaning ladies going to wash windows. Mother takes wash all the windows 5 hours, the grandmother 3 times longer and Paula wash all windows in 5 hours. How many hours will spend washing the windows this "women's team" if working togethe - ABS

What is the value of ? ? - 2nd class variations

From how many elements you can create 6480 variations of the second class? - Radius

Determine the radius of the circle, if its perimeter and area is the same number. - Circle chord

What is the length d of the chord circle of diameter 58 mm, if distance from the center circle is 24 mm? - Number

What number is 24 % smaller than the number 51? - Garden

Father dig up the garden in 13 hours. Son in 18 hours. How many hours take dig up the garden together? - Excavation

Mr. Radoslav calculated that excavation for a water connection dig for 10 days. His friend would take 7 days. Radoslav worked 3 days alone. Then his friend came to help and started on the other end. On what day since the beginning of excavation they met? - Accidents

The count of accidents in 1993 caused 8009 women which is 7.1%. How many men caused the accidents? - River

Calculate how many promiles river Hudson average falls, if on section long 921 km flowing water from 1224 m AMSL to 154 m AMSL. - Powers

Is true for any number a,b,c,d equality:? ? - Gauss

Help little C.F. Gauss sum all the integers from 1 to 340.

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