Answer:
78% (to the nearest tenth)
Step-by-step explanation:
Volume of a cube = (length )³
Let the length of the cube = y
Original volume = y³
if the length is decreased by 40%, then new length = 1- (40% of y)
= 1-0.4y
= 0.6%
New volume (after decreasing the length) = (0.6y)³
= 0.216y³
% Volume decrease = (Original volume - New volume)/Original Volume x 100%
= (y³ - 0.216y³)/ y³ x 100%
= 0.784y³/y³ x 100%
=78.4%
≈78%
