What is the L stand for in sts-51-l?

Half past 8 it's the same thing as 830? A private plane leaves an airport and flies due east at 192 miles per hour Two hours later a jet leaves the same airport and flies due east at 960 miles per hour How long will the private plane fly? What is 300 plus 25? What number goes in to 15 and 100? A railwway tunnel in shape of circle has diamet 4.8m. AB is a horizontal line representing the ground rails are laid on and is 3.2m. How do you calculate the height from ground to top of tunnel? Is -2 degree colder than -1 degree? Is one foot greater than 1 inch? Is a square always trapazoid? Is 20 over 45 equivalent to 4 over 8? What is the area of the parallelogram of 17cm x 20cm x 30cm? Why do you have names instead of numbers? What adds up -13 but multiplies to 18? What do you times to 23 to get 60? How do you diameter of a circle? What is a equivilant fraction for 54 over 72? Which type of graph would you use to show the number of students in each grade? Convert 20 decimeters into inches? The loop decision point consist of three features? How many is in one dozen? How must an operator measure the length of hisher vessel?