Divide the perimeter by 2, this will give you the sum of one length and one width.
68/2 = 34 yards
Now the length is 10 yards more, so subtract 10 from the 34 and divide by 2 again:
34 - 10 = 24
24 /2 = 12
The width is 12 yards.
The length is 12 + 10 = 22 yards.
Call the price of the bike before mark up 'x', then we have:
x + 0.25x = 210
1.25x = 210
x = 168
Therefore, the bike cost $168 before 25% price increase.
Answer:
X-8 is the best answer there