Alexander B. answered • 09/11/15

PhD in Engineering with 15 Years of Outlook Experience

First, notice that $6.40 = 640 cents. The corresponding linear equation and a solution is shown below in several steps:

Original equation for amount of Dimes (D):

Original equation for amount of Dimes (D):

**10*D + 25*(D+2) +5*4*(D+2) = 640**

Simplified as following, resulting in the answer for D:

55*D=550

**D=10**

thus having the amount of Quarters:

**Q=12**

and correspondingly, amount of Nickels:

**N= 48**

The equation can be easily solved online using Linear Equation Solver (http://examn8.com)

Hope this will help. Best regards,