Problema Solution

select the set of euations that represents the following sitiuation:Mary invested one amount at 10% simple intrest,and a second amount at 3%intrest,earning$21.72 in one year.Ifshe had switched te amounts,she would have earned%15.07.What were the two amounts?

10x+3y=15.07;10x+3y=21.72

10x+3y=21.72;10y+3x=15.07

0.10x+0.03y=21.72;0.1y+0.03x=15.07

0.10x+0.03y=15.07;0.10x+0.03y=21.72

Answer provided by our tutors

The two amounts are x and y

The earnings are 0.10x + 0.03y = 21.72

If she had switched te amounts, the earnings are 0.10y + 0.03x = 15.07

So we choose 0.10x+0.03y=21.72;0.1y+0.03x=15.07