The first answer is wrong, you should use the formula by putting the initial mass first, like this: (6.00g-4.50g)/3min
=(1.50g)/3min =0.50g/min And in the second one you just have to do a rule of 3. 6g-4.5g=1.5g
1.5g --> 3min
? --> 1min 1.5g(1min)/3min= 0.5g
6g-0.5g=5.5g
