Answer:
3
Step-by-step explanation:
If 6 numbers have a mean value of 10, it means that the sum of the numbers divided 6 is equal to 10. This can be expressed as:
x÷6=10
x=60
The new number added will be the 7th number and now the mean is 9. You have to ask what number divided by 7 is equal to 9? This can be expressed as:
y÷7=9
y=63
63-60=3
So the new number added is 3
Y/3 + 1/4 = 5/12
4y/12 + 3/12 = 5/12
4y/12 = 2/12
4y = 2
/4 /4
y = 1/2
Therefore y = 1/2
B and C can be divided by 9.
Divide 15 by 2, then square the amount.
(15/2)^2 = 225/4
3/5×1/3=1/5×1/1=1/5 so 1/5 is you answer