Mathematics is one of the most difficult subjects. [Positive Degree]

• One of the যুক্ত Superlative Degree কে Positive Degree করার নিয়ম:
- Very few বসে।
- Superlative Adjective এর পর থেকে বাকি অংশ বসে।
- Verb এর Plural form বসবে।
- As/So + Superlative Adjective positive form + As.
- প্রদত্ত Sentence এর Subject বসে।

Superlative: Iron is one of the most useful metals.
Positive: Very few metals are as useful as iron.

Superlative: Mathematics is one of the most difficult subjects.
Positive: Very few subjects are as difficult as mathematics.

Other options,

খ) No other subjects are as difficult as mathematics.
- "One of the most" থাকলে "No other" ব্যবহার হয় না। আর "subjects" plural হলে "No other subject" singular হবে।

গ) No other subject is as difficult as mathematics.
- "One of the most" → "No other" ভুল প্রয়োগ।

ঘ) Very few subjects is as difficult as mathematics.
- "subjects" plural, তাই "are" হবে, "is" নয় — subject-verb agreement ভুল।