a)
a= numarul tau
a:5=2, rest ?... rest=0=>a=5x2=10
rest=1
a=5x2+1=>a=11
rest=2=>a=5x2+2=>a=12
rest3=>a=5x2+3=>a=13
rest4=>a=5x2+4=14... rest nu este 5 deoarece o sa dea catul 3
b) a= numarul tau
a:7=36, rest >3
rest=4=>a=36x7+4=256
rest=5=>a=36x7+5=257
rest=6=>a=36x7+6=258
c) a= numarul tau
a:9=28, rest<4
rest=3=>a=9x28+3=255
rest=2=>a=9x28+2=254
rest=1=>a=9x28+1=253
rest0=>a=9x28=252