Answer:
$2
Step-by-step explanation:
One group consisting of one of each of the coins has a value of $0.40. The least common multiple of $0.40 and $1.00 is $2.00.
___
In cents, ...
40 = 2^3 · 5
100 = 2^2 · 5^2
The LCM is 2^3 · 5^2 = 200. This is the product of the highest powers of the prime factors of the two numbers.