You can put this solution on YOUR website!
First let's figure out how many mathematicians are already on the team:
20 members times 20% is the same as:
20*.2 = 4
So, there are already 4 mathematicians on the team.
We need to add x more mathematicians.
Whenever we add x mathematicians, we add x to the original 4 mathematicians,
and we also add x to the number of total team members.
We need to find the value for x which provides a ratio of 10/11:
Multiply both sides by 11:
Distribute the 11 on the left and "cross out" 11/11 on the right:
Multiply both sides by (20 + x)
"Cross out" (20 + x)/(20 + x) on the left and distribute the ten on the right:
Subtract 10x and 44 from both sides to isolate the variable:
44 + 11x - 44 - 10x = 200 + 10x - 44 - 10x
x = 200 - 44
x = 156
So, we need to add 156 mathemeticians to the team.