
Given, difference of the lengths of major and minor axis is 10.
⇒2b−2a=10 … (1)
One of the focii is (0,53)
⇒be=53 … (2)
Also a2=b2(1−e2) .......(3)
⇒a2=b2−75
⇒(b−a)(a+b)=75
⇒a+b=15 … (4)
From (1) and (4)
a=5 and b=10
Hence length of the latus rectum =b2a2=2⋅1025=5