Im thinking 10 because 10+40=50 and 10x7=70
A ratio indicates how many times one number contains another examples 4:3 2:3
To work out the profit, firstly, you have to work out the cost of buying them, which is $15 multiplied by 100, which is $1500. You then have to work out what he sold them all at, which is $29.99 multiplied by 100, which is $2999. You then have to subtract $1500 from $2999, giving you $1499. Therefore, Ace made $1499 in profit.
Hope this helps :)
Answer:

Step-by-step explanation:
we know that
The density is equal to the mass divided by the volume
Let
x-----> the mass of marble
y----> the volume of marble
z----> the density of marble

in this problem we have


substitute and solve for x

