इस सवाल का हल आसान है।

इस means this here, but specifically in its oblique form.

In Hindi, यह changes to इस when it comes before a noun that is connected to a postposition or a postposition-like marker later in the noun phrase. Since the phrase is इस सवाल का (of this question), Hindi uses इस, not यह.

Compare:

• यह सवाल = this question
• इस सवाल का हल = the solution of this question

So यह is the basic form, and इस is the form used in constructions like this one.

सवाल means question.

It is a very common everyday word. A more formal Sanskrit-based word is प्रश्न, which also means question.

So these are both possible:

• इस सवाल का हल आसान है।
• इस प्रश्न का हल आसान है।

The first sounds more everyday and conversational.

हल means solution or way to solve.

It is often used for something like a problem, exercise, puzzle, or question that has to be worked out.

So in this sentence, सवाल का हल means:

• the solution to the question
• the way to solve the question

It is different from जवाब, which usually means answer.

A useful contrast:

• सवाल का जवाब = the answer to the question
• सवाल का हल = the solution/worked-out solving of the question

In math or logic contexts, हल is especially natural.

का shows a relationship like of or 's.

So:

• इस सवाल का हल literally = this question's solution
• more natural English = the solution to this question

Hindi often uses का / की / के where English might use of, to, or 's.

Here, का agrees with हल, not with सवाल.

Since हल is masculine singular, Hindi uses का.

Because का / की / के agrees with the noun that comes after it—in this case, हल.

Here is the breakdown:

• हल = masculine singular
• so the correct form is का

Compare:

• इस सवाल का हल = the solution of this question
• इस किताब की कीमत = the price of this book
  (की because कीमत is feminine)
• इन सवालों के हल = the solutions of these questions
  (के because हल is plural)

So the form depends on the gender and number of the possessed thing, not the first noun.

The order is:

this question + of + solution

More literally:

• इस = this
• सवाल = question
• का = of
• हल = solution

So Hindi builds the phrase as of this question, the solution.

English usually says:

• the solution to this question
• or this question's solution (less common)

This kind of noun phrase is very normal in Hindi:

• राम की किताब = Ram's book
• मेरे दोस्त का घर = my friend's house
• इस सवाल का हल = the solution to this question

Because आसान is an invariable adjective in Hindi.

Some Hindi adjectives change form depending on gender/number, especially adjectives ending in -ा, such as:

• अच्छा लड़का
• अच्छी लड़की
• अच्छे लड़के

But आसान does not change:

• आसान सवाल = easy question
• आसान किताब = easy book
• आसान हल = easy solution

So आसान stays the same whether the noun is masculine, feminine, singular, or plural.

है is the present-tense form of to be: is.

Hindi often puts the main descriptive part first and the copula at the end.

So:

• इस सवाल का हल आसान है।
• literally: This question's solution easy is.
• natural English: The solution to this question is easy.

This final है is very common in simple statements:

• यह किताब अच्छी है। = This book is good.
• कमरा बड़ा है। = The room is big.
• हल आसान है। = The solution is easy.

No, they mean different things.

• यह सवाल आसान है। = This question is easy.
• इस सवाल का हल आसान है। = The solution to this question is easy.

These are close in meaning, but not identical.

The first describes the question itself as easy.
The second focuses on the solution/process of solving it.

In many situations they may imply something similar, but grammatically they are different statements.

Yes, but the meaning or tone changes a bit.

• प्रश्न = question (more formal)
• सवाल = question (common everyday word)
• समस्या = problem

So:

• इस प्रश्न का हल आसान है। = The solution to this question is easy.
• इस समस्या का हल आसान है। = The solution to this problem is easy.

All are grammatical, but choose the noun based on what you mean.

Yes, हल is masculine.

One clue in this sentence is the use of का:

• इस सवाल का हल

Since का agrees with हल, that tells you हल is masculine singular.

Another way learners often notice gender is by seeing words used in many examples over time. Hindi gender is not always predictable from the form alone, so exposure helps.

Yes. Then several parts would change:

• इन सवालों के हल आसान हैं।

Breakdown:

• इन = these (oblique plural)
• सवालों = questions
• के = of (agreeing with plural हल)
• हल = solutions
• आसान = easy
• हैं = are

So the original singular sentence:

• इस सवाल का हल आसान है।

becomes plural:

• इन सवालों के हल आसान हैं।

Yes—in translation, sometimes the best English equivalent is to, even though Hindi uses का.

Hindi is not matching English word-for-word here. The Hindi structure is more like:

• the question's solution
• the solution of the question

But natural English often prefers:

• the solution to the question

So when you translate, focus on the relationship, not on forcing का to equal only of every time.

Not usually in the same sense.

• जवाब = answer
• हल = solution

If the sentence is about solving something—especially a math question, puzzle, or problem—हल is better.

For example:

• इस सवाल का जवाब सही है। = The answer to this question is correct.
• इस सवाल ka हल आसान है। = The solution to this question is easy.

So जवाब and हल are related, but they are not always interchangeable.