(1/6+1/7+1/8+..............+1/30)<5
de la 1/6 pana la 1/30 sunt 30-6+1=25 de fractii
1/6+1/7+1/8+..............+1/30< 1/6+1/6+1/6+….+1/6; (de 25 de ori 1/6)
1/6+1/7+1/8+..............+1/30<25/6=125/30<150/30=5
=> 1/6+1/7+1/8+..............+1/30<5 (A)
