Your answer, "700", is not correct.
The correct answer to
How many horsemen did David take from Hadadezer?
is
7,000
as shown by
1 Chronicles 18:4
which is
- KJV
- And David took from him a thousand chariots, and seven thousand horsemen, and twenty thousand footmen: David also houghed all the chariot horses, but reserved of them an hundred chariots.
- NIV
- David captured a thousand of his chariots, seven thousand charioteers and twenty thousand foot soldiers. He hamstrung all but a hundred of the chariot horses.