contestada

In a collection of nickels, dimes, and quarters worth $6.90, the ratio of the numbers of nickels to dimes is 3:8. The ratio of the number of dimes to quarters is 4:5. Find the number of each type of coin. (hint: make a coin value chart.)

Respuesta :

[tex]3n=8d\\4d=5q\\8d=10q=3n\\0.05(3n)+0.1(8d)+0.25(10q)=6.90\\0.15n+0.8d+2.5q=6.90\\\\0.15+0.8+2.5=3.45\\\frac{6.90}{3.45}=2\\2(0.15n+0.8d+2.5q)-6.90\\0.05(6n)+0.1(16d)+0.25(20q)=6.90\\6n,16d,20q[/tex]

Six nickels, sixteen dimes, twenty quarters.