Răspuns:
Explicație pas cu pas:
4·a + 30 min + 45 min = 10 ore
a = timpul comun
10 ore = 10 x 60 min = 600 min =>
4·a + 75 min = 600 min =>
4·a = 600 min -75 min = 525 min =>
a = 525 min : 4 = 131 min 15 sec =>
B a petrecut = 131 min 15 sec ; adica : 2 ore 11 min 15 sec
R a petrecut = 131 min 15 sec ; adica : 2 ore 11 min 15 sec
C a petrecut 131 min 15 sec + 30 min = 161 min si 15 sec
adica : 2 ore 41 min 15 sec
M a petrecut 131 min 15 sec + 45 min = 176 min 15 sec
adica : 2 ore 56 min 15 sec
In total :
B+C+M+R = 2 ore 11 min 15 sec + 2 ore 41 min 15 sec +
+ 2 ore 56 min 15 sec + 2 ore 11 min 15 sec =
= 8 ore 119 min 60 sec = 8 ore 120 min = 10 ore
