The ratio given in the problem for each booster is 660300 Kg of propellant in 2.5 min. To find how much propellant does each burn in 1 minute we will divide this amount.
[tex]\frac{660300\text{ kg}}{2.5\text{ min}}=\frac{264120\text{ kg}}{1\min }[/tex]Each booster burns 264120 kg in 1 min.