The Bhai-Bhai Problem

So, you got a question like this- A & B agreed to start a partnership firm, they signed a partnership deed where B has 60% of the capital. The deed says that profits will be divided in the ratio of 7:3, and losses will be borne in the same ratio. One day, A gives 10% of his share to C and asks B to give him some percentage of the profits as well. B agrees, and they make a new agreement, but this one doesn't mention anything about losses. Now, the question is, if there are losses, will they be borne in the 7:3 ratio or not?

Most people get this wrong thinking B will always have to bear 60% (70%) of the losses because the deed says so. But, nope, losses only arise when there are actually losses, right?