Answer:
(1) The ratio of number of $5-bill to number of $10-bill is: 1/4;
(2) The ratio of number of the $5-bill to number of $10-bill is: x/ [(72-x)/2] in which x is the number of $5-bill and x must be either 0 or an even positive integral ( as their is insufficient information given, there can be many ratios that suit into the given information as long as the condition on x is met).
Step-by-step explanation:
(1) Denote x is the number of $5 bill and y is the number of $10 bill, in which x and y should be >= 0 and is an integral number.
We have (x+y) / (5x + 10y) = 1/9 <=> 9x + 9y = 5x + 10y <=> 4x = y <=> x/y =1/4 .
(2) Denote x is the number of $5 bill, y is the number of $10 bill.
We have: 5x + 10y = 360 <=> x = [ 360 - 10y ] /5 <=> x = 72 - 2y <=> y = (72 - x)/2 => x/y = x/[(72-x)/2] in which x must be must be either 0 or an even positive integral so that y can be identified in order to match with the given information .
