Erica can run \dfrac{1}{6} 6
1
​
start fraction, 1, divided by, 6, end fraction of a kilometer in a minute. Her school is \dfrac34
4
3
​
start fraction, 3, divided by, 4, end fraction of a kilometer away from her home.
At this speed, how long would it take Erica to run home from school?

Can you me find the missing length. i attached an image.

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?

What is the length of the segment, endpoints of which are intersections of parabolas y=x2? 11 4 x? 7 4 and y=? 7 8 x2+x+ 31 8 ?