If a paint can holds 2.5 litres, whats the radius of the can if it has a height of 20 cm?

If u = < -7, 6> and v = < -4, 17> , which vector can be added to u + 3v to get the unit vector < 1, 0> as the resultant vector? a. < 18, -57> b. < 18, -45> c. < 20, -57> d. < 20, -45>