A clock face is viewed through a plane vertical mirror. The mirror image shows the time as 3:40. What is the actual time?
Actual time = 11:60 - Mirror time = 11:60 - 3:40 = 8:20.
What is the mirror image time when the actual clock time is 6:15?
Mirror time = 11:60 - 6:15 = 5:45.
If a square paper is folded in half horizontally, then folded in half vertically, and a triangular punch is made in the center, how many triangular holes will appear when the paper is completely unfolded?
The paper was folded into 4 layers (2 folds). One punch through all layers creates 4 hole patterns upon unfolding.
Consider a right circular cone. Which statements are correct about its orthographic views?
A right circular cone has a circular base and a triangular profile in any central vertical section.
Which statements about a sphere's orthographic projections are correct?
A sphere is rotationally symmetric, so its orthographic projection from each principal direction is a circle of the same outline.