Question 54028
let ,no. of hrs he worked on saturday=y
     "    "  "   "   "     "  weekdays=x
we have x+y=13
also x=13-y     (i)
now,
      3x+4y=43
using equation (i)
          3(13-y)+4y=43
           39-3y+4y=43
              y=4