Angol nyelvű szám, 2002. december
	Előző oldal	Tartalomjegyzék	Következő oldal	MEGRENDELŐLAP

New exercises for practice - competition C
(690-694.)

C. 690. Is it possible for the sum of the volumes of three cubes of integer edges to be 2002 units?

C. 691. Express in mm² the area of Hungary on a globe of radius 25 cm.

C. 692. For the real numbers x, y, z,

x+2y+4z\(\displaystyle \ge\)3 and y-3x+2z \(\displaystyle \ge\)5.

Prove that y-x+2z\(\displaystyle \ge\)3.

C. 693. In what interval may the apex angle of an isosceles triangle vary if a triangle can be constructed out of its altitudes?

C. 694. Evaluate the sum [log₂1]+[log₂2]+[log₂3]+...+[log₂2002].

Suggested by Ádám Besenyei, Budapest