Answer:
We have the ration:
3:5:7
This means that, if they receive $15, then:
Person A will get $3
Person B will get $5
Person C will get $10
Let's then define the amount of money shared as:
Amount = K*$15
where we want to find the number K.
In this scenario, each they will get:
Person A : $3*K
Person B: $5*K
Person C: $7*K
Now, we know that one of them gets "10 more than the other"
(The problem here is that we do not know exactly who receives more than who, i will suppose that person B receives $10 more than person A)
then we can have:
$5*K = $10 + $3*K
solving this for K, we have:
$5*K - $3*K = $10
$2*K = $10
K = $10/$2 = 5
Then the amount shared, in this situation, is:
Amount = K*$15 = 5*$15 = $75.