For Bank C$,$

when I use financial calculator,

If I put N$=24,$ P$/$Y$=12,$ C$/$Y$=12,$ PV$=50000,$ PMT$=-100,$ FV$=-50000$ and compute I$/$Y$,$ I get I$/$Y$=2\mathrm{.}4$

So I use $2\mathrm{.}4\%$ to find EAR:

ICONV $-$ NOM$=2\mathrm{.}4$; C$/$Y$=12,$ compute EFF then I get $2\mathrm{.}43$

Is there something wrong with my financial calculator numbers?