20 uždavinys

Sprendimas:

Iš viso mokinių yra $4+5+10+5+1$ = $25$

( 5* 4+ 6* 5+ 7* 10+ 8* 5+ 9* 1)

/ 25

( 5* 4+ 6* 5+ 7* 10+ 8* 5+ 9* 1)

/ 25

= $\frac{5\cdot 4+6\cdot 5+7\cdot 10+8\cdot 5+9\cdot 1}{25}$ =

(20+ 6* 5+ 7* 10+ 8* 5+ 9* 1)

/ 25

= $\frac{20+6\cdot 5+7\cdot 10+8\cdot 5+9\cdot 1}{25}$ =

(20+30+ 7* 10+ 8* 5+ 9* 1)

/ 25

= $\frac{20+30+7\cdot 10+8\cdot 5+9\cdot 1}{25}$ =

(20+30+70+ 8* 5+ 9* 1)

/ 25

= $\frac{20+30+70+8\cdot 5+9\cdot 1}{25}$ =

(20+30+70+40+ 9* 1)

/ 25

= $\frac{20+30+70+40+9\cdot 1}{25}$ =

(20+30+70+40+9)

/ 25

= $\frac{20+30+70+40+9}{25}$ =

(50+70+40+9)

/ 25

= $\frac{50+70+40+9}{25}$ =

(120+40+9)

/ 25

= $\frac{120+40+9}{25}$ =

(160+9)

/ 25

= $\frac{160+9}{25}$ =

169

/ 25

= $\frac{169}{25}$ =

6.76 $6.76$

Atsakymas: 6.76

19 uždavinys21 uždavinys