There are two shipping options available: land and air. all three can be shipped simultaneously regardless of travel option chosen. travel speeds are as follows: land: vland = 50tair: vair = 200twhere t is time in seconds. also, sland = 0 and sair = 0 at t = 0, if sland and sair are the distances traveled at time t by the two possible means of transportation. it takes 200 seconds to ship all three from a to b by land. how long does it take by air?