answer mate: 3/5
Explanation:
Tim buys 2/5 of brownies out of the brownies pan that has 3/10 brownies.
meaning it will be 3/10 - 2/5 to find the remaining brownies in the pan which is -1/10.
so to get the total amount of brownies it will be all the fractions added together which is 3/10 + 2/5 + -1/10 = 6/10 broken down to 3/5.