Polygons

2000005510

Level: 
A
The lengths of the sides of the rectangular garden are in the ratio 3:4. The line connecting the centers of adjacent sides is 25m long (see the picture). How long will it take for the owner to till the whole garden if he digs over 1200dm2 per hour?
100 hours
50 hours
30 hours
40 hours

2000005504

Level: 
A
Let ABCD be an arbitrary convex quadrilateral and let’s denote by P, Q, R, S the centers of the sides AB, BC, CD, DA in that order. Then, what type of a quadrilateral is PQRS?
It may or may not be a parallelogram.
It is a rectangle.
It is a rectangle or a square.
It is not a parallelogram.