Blank of electromagnetic radiation is visible to the human eye

Aschool principal ordered 1,000 pencils. he gave an equal number to each of 7 teachers untill had given out as many as possibe. how many pencils were left?

Can someone me? i need to have this done as soon as possible! i'm putting 20 points on this!

What is the difference between the cultures of central asia and the caucasus region? the majority of people in central asia are muslim; the majority in the caucasus region are christian. the primary language in central asia is armenian; the primary language in the caucasus region is russian. central asia has been plagued by ethnic unrest; the caucasus region has had little ethnic conflict. the effects of soviet rule can still be seen in central asia; the caucasus region has developed its own identity since the fall of the ussr.