Find a rational number halfway in between the two numbers 7/8 and 2/7

In a school 2/3 of the students study a language of those who study a language 2/5 study french

Me! 50 points! why does when we come home, our door is unlocked and there is grease on the door knob, me solve this , and i don't know what category this goes under

How do businesses a country's economy? a. by investing in goods and services b. by increasing the unemployment rate c. by making profits