11 -
Let the numbers of hours worked by Isaac = H
Ruby worked = H + 6
Svetlana worked =4*[H + 6]
H + H + 6 + 4*[H + 6] = 126
6H + 6 + 24 = 126
6H = 126 - 6 - 24
6H = 96
H = 96 / 6 = 16 Hours worked by Isaac.
16 + 6 = 22 Hours worked by Ruby
4 * 22 = 88 Hours worked by Svetlana.
So that: 16 + 22 + 88 = 126 Hours worked by all.
