Answer:
The correct answer is 25
Explanation:
See the attached figure.
SAS similarity theorem mean that when two triangles have corresponding angles are congruent and corresponding sides with identical ratios the triangles are similar.
So, if ΔONM similar ΔSRQ by the SAS similarity theorem
∴∠N = ∠R
And

given that NM = 10 , NO = 8 , QR = x , RS = 20
∴

∴

So, the value of x will make ONM similar SRQ by the SAS similarity theorem = 25