Here the two samples should be comparable .
The total number of cows in the farm = 200
the total number of cows giving milk = 150
the total number of cows in corral = 20
Suppose total number of cows giving milk in corral = x
The ratio of the total number of cows present to the total number of cows giving milk should be same in farm and corral
so : 200 = 20
------- -------
150 x
now we do cross multiplication :
200 x = 150* 20
200x = 3000
x= 3000/200
x= 15
SO we expect 15 cows in corral should be giving milk .
Answer : 15
For one pie , she will use 2.3 cups of flour .
I believe the answer is 45.
The wording is confusing but I am going to guess it is 5(n+1)=2(n+7). So 5xn=5n and 5x1=5. 5n+5=2(n+7). Then 2xn=2n and 2x7=14. The question now stands 5n+5=2n+14. Then 5n+2n=7n and 14-5=9. So, you have 7n=9. Then you divide both sides by 7 and get n=1.2857...