Given edge of three solid cubes are 3 cm , 4 cm and 5 cm respectively
Volume of cube =(side)3
Volume of first cube =(3)3=27cm3
Volume of second cube =(4)3=64cm3
And Volume of third cube =(5)3=125cm3
∴ Sum of volume of three cubes =(27+64+125)=216cm3
Let the edge of the resulting cube = R cm
Then,
Volume of the resulting cube
R3=216 cm3
∴R=3√216 cm3
⇒R=6 cm