I HV A IFB 25CS1 MICROWAE+CON+GRILL PLS TELL HOW TO BAKE A CAKE

SOURCE: cooking temp to bake cake inn convection mode samsung model

Hi I guess you are cooking usng the combination setting? if so The cake will be hard due to increased microwave energy, I would suggest reducing the microwave energy on the Samsung unit when using the combination setting.

Hope this helps

SOURCE: I hv got a ifb

You should be using convection mode first of all. It's not clear from your post if you are. Also looks like you're oven is baking at higher temperature than it says. Try 170 degrees for 13-14 mins instead.