It is not 7 it is 12. 3x4 = 12
3/6 of the beads are purple
3/6 simplified = 1/2
1/2 of 18, or 18/2 = 9
9 beads are purple
hope this helps
Let Karen works x hours baby sitting
So, she worked (18-x) hours giving music lessons
So,
According to question
5x + 12(18-x)=139
This gives
7*x=77
x=11
So,
<span>Karen worked <em>11 hours baby sitting </em>and (18-11)=7 hours giving music lessons</span>
Please restore my faith in humans and try to understand this concept