Disciples sent for a colt/ass

Mark 11:1b [1] [A]t the mount of Olives, he sendeth forth two of his disciples, Matt 21:1b [U]nto the mount of Olives, then sent Jesus two disciples, Luke 19:29 And it came to pass, when he was come nigh to Bethphage and Bethany, at the mount called the mount of Olives, he sent two of his disciples,
Mark 11:2 And saith unto them, Go your way into the village over against you: and as soon as ye be entered into it, ye shall find a colt tied, whereon never man sat; loose him, and bring him. Matt 21:2 Saying unto them, Go into the village over against you, and straightway ye shall find an ass tied, and a colt with her: loose them, and bring them unto me. Luke 19:30 Saying, Go ye into the village over against you; in the which at your entering ye shall find a colt tied, whereon yet never man sat: loose him, and bring him hither.
Mark 11:3 And if any man say unto you, Why do ye this? say ye that the Lord hath need of him; and straightway he will send him hither. Matt 21:3 And if any man say ought unto you, ye shall say, The Lord hath need of them; and straightway he will send them. Luke 19:31 And if any man ask you, Why do ye loose him? thus shall ye say unto him, Because the Lord hath need of him.
Matt 21:4 All this was done, that it might be fulfilled which was spoken by the prophet [2], saying, 5 Tell ye the daughter of Sion, Behold, thy King cometh unto thee, meek, and sitting upon an ass, and a colt the foal of an ass. John 12:14 [3] And Jesus, when he had found a young ass, sat thereon; as it is written [2], 15 Fear not, daughter of Sion: behold, thy King cometh, sitting on an ass's colt. 16 These things understood not his disciples at the first: but when Jesus was glorified, then remembered they that these things were written of him, and that they had done these things unto him.
Mark 11:4 And they went their way, and found the colt tied by the door without in a place where two ways met; and they loose him. Matt 21:6 And the disciples went, and did as Jesus commanded them, Luke 19:32 And they that were sent went their way, and found even as he had said unto them.
Mark 11:5 And certain of them that stood there said unto them, What do ye, loosing the colt? Luke 19:33 And as they were loosing the colt, the owners thereof said unto them, Why loose ye the colt?
Mark 11:6 And they said unto them even as Jesus had commanded: and they let them go. Luke 19:34 And they said, The Lord hath need of him.
Mark 11:7 And they brought the colt to Jesus, and cast their garments on him; and he sat upon him. Matt 21:7 And brought the ass, and the colt, and put on them their clothes, and they set him thereon. Luke 19:35 And they brought him to Jesus: and they cast their garments upon the colt, and they set Jesus thereon.
       

[1]Compare Mark 11:1-6 to Mark 14:13-16.

[2]Zechariah 9:9 Rejoice greatly, O daughter of Zion; shout, O daughter of Jerusalem: behold, thy King cometh unto thee: he is just, and having salvation; lowly, and riding upon an ass, and upon a colt the foal of an ass. Note that, in order to closely match the prophecy, Matthew has Jesus riding into Jerusalem on two animals at the same time.

[3]This section from John cannot be reconciled with the other gospels as it has Jesus locating the animal himself.