Răspuns:
1. 4 c=20 => 1 c=20:4=5 lei (1 caiet)
5*102=510 lei
2. a+b+c+d= 98 lei b=a+1 c=a=2 d=a+3 consecutive
a+a+1+a+2+a+3=98 4a=98-6= 92 4a=92 a= 92:4=23
numerele sunt 23, 24, 25, 26
Verif 23+24+25+26=98
3. 400 :5=80 km intr-o ora
500:80=6,2 adica in 6ore si 20 min
4. a+b= 215 a-b=71 => a=71+b inlocuim in a+b
71+b+b=215 2b= 215-71 2b=144 b= 72
a=72+71=143 Verif : 143+72=215
5. 3robinte .........12 ore
4 robinete .......x
3/4=12/x => x= 12 *3/4= 36:4= 9 ore
4 robinete umplu in 9 ore
6. 4 caiete.....5 pixuri.....26 lei / × 7
7 caiete.....3 pixuri.....34 lei / × 4 28 caiete.....35 pixuri.....182 lei
28 caiete.....12 pixuri.......136 lei se scad si obtinem 35p- 12p= 182-136
23pixuri= 46 lei => 1 pix= 46:23=2 lei 1 pix costa 2lei
4 c+ 5*2 = 26 lei 4c= 26-10= 16 lei 4 caiete=16 lei =>
1caiet=16 :4=4 lei 1 caiet costa 4 lei
7. [(2a-50)*3+150 ] :15=100
(2a-50)*3 +150= 100*15=1500
(2a-50)*3=1500-150=1350
2a-50=1350 :3 =450 2a-50=450
2a= 450+50=500 a=500:2=250
a=250 Verif 500- 50=450 450*3=1350 1350+150=1500
1500:15=100
8. PP ca toate bancnotele sunt de 100 lei
100*50=5000 lei
5000-3000 =2000 lei diferenta
100-50=50 lei
2000:50=40 de bancnote de 50 lei
50-40=10 bancnote de 100 lei
