Sumita is making 7 flapjacks because the recipe states 30 g and if all the ingredients of the recipe make 14 flapjacks, and 15 g of the sultanas are half of the amount shown in the recipe, then we have to divide the 14 from 2 to get 7 flapjacks.
If they are using 15 g when the recipe says 30 g is for 14 flapjacks. This means that the recipe is going to be cut in half because 30/2 is 15. So, half of 14 is 7. The answer, if I'm not mistaken, is going to be 7 flapjacks.