All were stationed at Pearl Harbor. How many were bombed during the attack?
Answer: None of them. All three were away from Pearl Harbor at the time of the attack.
As for where they were on that ill-fated day, and why:
Enterprise: On 28 November 1941, Admiral Husband E. Kimmel sent TF-8, consisting of Enterprise, the heavy cruisers Northampton (CA-26), Chester (CA-27), and Salt Lake City (CA-24) and nine destroyers under Vice Admiral William F. Halsey, Jr., to ferry 12 Grumman F4F-3 Wildcats of Marine Fighting Squadron (VMF) 211 to Wake Island. Upon completion of the mission on 4 December, TF-8 set course to return to Pearl Harbor. Dawn on 7 December 1941 found TF-8 about 215 miles west of Oahu.
Lexington: On 5 December 1941, TF-12, formed around Lexington, under the command of Rear Admiral John H. Newton, sailed from Pearl to ferry 18 Vought SB2U-3 Vindicators of Marine Scout Bombing Squadron 231 to Midway Island. Dawn on 7 December 1941 found Lexington, heavy cruisers Chicago (CA-29), Portland (CA-33), and Astoria (CA-34), and five destroyers about 500 miles southeast of Midway. The outbreak of hostilities resulted in cancellation of the mission and VMSB-231 was retained on board [they would ultimately fly to Midway from Hickam Field on 21 December].
Saratoga: The Saratoga, having recently completed an overhaul at the Puget Sound Navy Yard, Bremerton, Washington, reached NAS San Diego [North Island] late in the forenoon watch on 7 December. She was to embark her air group, as well as Marine Fighting Squadron (VMF) 221 and a cargo of miscellaneous airplanes to ferry to Pearl Harbor.
Yorktown (CV-5), Ranger (CV-4) and Wasp (CV-7), along with the aircraft escort vessel Long Island (AVG-1), were in the Atlantic Fleet; Hornet (CV-8), commissioned in late October 1941, had yet to carry out her shakedown. Yorktown would be the first Atlantic Fleet carrier to be transferred to the Pacific, sailing on 16 December 1941.