HP Deskjet F2100 Printer seriesで
HP 21 Black 185 standard pages
HP 22 Tri-c 170 standard pages
ttp://www.hp.com/pageyield/us/en/DJF2100/index.html

hp56/57に近い　HP Deskjet F4100 Printer series
HP 54 Black 600 standard pages
(with HP 57 Tri-color Inkjet Print Cartridge)
HP 21 Black 185 standard pages
(with HP 22 Tri-color Inkjet Print Cartridge)

HP 57 Tri-c 510 standard pages
(with HP 54 Black Inkjet Print Cartridge)
HP 22 Tri-c 170 standard pages
(with HP 21 Black Inkjet Print Cartridge)

hp56/57のインク少ないのがhp21/22なのかな？