Answer:
1500000 gallons.
Step-by-step explanation:
To solve this problem we can use the scientific notation.
Currently, all tanks at the aquarium have a combined volume of 1.25 x 10⁶ gallons.
The new tank has a volume of 250000 gallons, this number can be written as .25 x 10⁶
Now we're going to sum up the two quantities to find out the volume (both numbers have the same potency of 10):
(1.25 x 10⁶) + (.25 x 10⁶) = 1.50 x 10⁶.
Therefore, the volume of all the tanks will be 1.5 x 10⁶ gallons, which can also be written as 1500000 gallons.
