The student lockers at Euler High School are to be numbered consecutively from 1 to 500 using plastic digits which cost 5 cents each. What is the total cost of all the digits?

Question

mokeira · Answer

$$500\times5=2500cents$$

mokeira · Answer

$25

jack1 · Answer

...wouldn't students lockers from 10 to 99 each cost 10c...?
and from 100 to 500 each cost 15c...?

jack1 · Answer

so (500 * 15) - (99 * 5) - (9 * 5) ...?

jack1 · Answer

I got somewhere around the 6960c ballpark ... so $69.60

jack1 · Answer

does this make sense @Sepeario ...?

sepeario · Answer

thanks @Jack1 that was really helpful

jack1 · Answer

nah man, all gud hay  ;)

sepeario · Answer

what was the exact sum that you did? @Jack1

jack1 · Answer

sorry man, fell asleep and left lappy on, mah bad
so exact sum:

5c per digit
so first work out how many digits there will be:
500 numbers

9 have only 1 digit (numbers of 1 to 9) = 9 x 0.05 = $ 0.45
90 have only 2 digits (numbers of 10 to 99) = 90 x 0.10 = $9.00 
401 have have 3 digits (numbers 100 to 500) = 401 x 0.15 = $60.15

so total = 60.15 + 9 + 0.45 = $69.60 total