Răspuns:
a= bani cheltuiti, b= excursia, R = rest, t= total
a= 13.2% *t |_|_|_|_|_|_|_|_|_|_| ( 10 parti)
a= [tex]\frac{132}{10}* \frac{t}{100}[/tex]= [tex]\frac{33t}{250}[/tex]
781,20 = 3/5 *R => R= 781,20x5:3= 3906:3= 1302 (rest= 5 parti)
1302:5= 260.4 (o parte)
260,4 x2= 520,8 lei excursia R1= t-a= t- [tex]\frac{33t}{250}[/tex]=[tex]\frac{250t- 33t}{250}[/tex]= [tex]\frac{217 t}{250}[/tex]
1302=[tex]\frac{217 t}{250}[/tex]=> t= 1302*250/217 = 1500 lei total
a= [tex]\frac{33*1500}{250}[/tex]= [tex]\frac{49500}{250}[/tex]= 198 lei a cheltuit (13.2%)
