**Agnes had 4 times as many blue beads as yellow beads. For every 5 beads she used to make a necklace, she used 3 yellow beads. She completed the necklace after she had used up all the yellow beads. If she had 35 blue beads left, how many yellow beads did she have at first?**

Source: SCHOOL

PLEASE HELP thks

Source: 2016 SA2