how to get the answer 900 square ft3 using 6cm3 and 15cm3

I have no idea. It looks like typos or missing information.

assuming you meant 900 cm^3, then

50*6cm^3 + 40*15cm^3 = 900 cm^3

There's no such thing as "square ft^3"

However, 10 * 6cm^3 * 15cm^3 = 90 (cm^3)^2

To get the answer in square feet (ft^2) using the given values of 6cm^3 and 15cm^3, we would first need to convert the given values to their corresponding unit of measurement in square feet.

To do this, we need to know the dimensions of the space or object we are measuring in order to calculate the area. Assuming we have a rectangular shape, we would need to know either the length and width or the height and base length of the shape.

Once we have the dimensions, we can calculate the area in square centimeters (cm^2). To convert from cm^2 to ft^2, we need to use the conversion factor:

1 ft = 30.48 cm

To convert from cm^2 to ft^2, we would need to divide the area in cm^2 by 929.03.

Let's assume we have the dimensions and the area in cm^2. We can now calculate the area in ft^2:

1. Find the area in cm^2:
- Let's assume the area is 6 cm^3
- Convert cm^3 to cm^2 if necessary, assuming it's already in cm^2

2. Convert the area in cm^2 to ft^2:
- Divide the area in cm^2 by 929.03

3. The resulting value is the area in ft^2.

Repeat the same process for the second given value of 15 cm^3 to get the area in ft^2.

Please note that this method assumes a rectangular shape and the given values represent the volume of the shape. If you have different measurements or a different shape, the process will vary.