Ceramic disc tap problem?

The left knob is the hot one, and earlier this week I was turning the knob to turn the tap on and heard like a click/snap, Its like something snapped inside the knob, and now the knob is sort of loose when I turn, so of course I havent used it, so was boiling kettle for hot water till I got it fixed.
Blow me, now the right one (cold) has gone just now, exactly the same as the hot tap.
I was going out anyway to buy washers thinking I will change the washer on the original hot one, but now after the cold knob has gone the same, is it the washer, cartridge or something else?