With reference to Indian history, consider the following statements:

1. The first Mongol invasion of India happened during the reign of Jalal-ud-din Khalji.
2. During the reign of Ala-ud-din Khalji, one Mongol assault marched up to Delhi and besieged the city.
3. Muhammad-bin-Tughlaq temporarily lost portions of north-west of his kingdom to Mongols. Which of the statements given above is/are correct?

Let's analyze each statement regarding Mongol invasions:

Statement 1 is incorrect: The first Mongol invasion of India occurred during the reign of Iltutmish in 1221 AD. Changez Khan reached the Indus River while pursuing Jalaluddin, the Khwarizmi prince.

Statement 2 is correct: During Ala-ud-din Khalji's reign, a significant Mongol assault, the fourth invasion, led by Targhi with 120,000 horsemen, reached Delhi and besieged the city in 1303 A.D. This happened shortly after Ala-ud-din's return from Chittor.

Statement 3 is incorrect: Major Mongol invasions occurred after the Khiljis were replaced by the Tughlaq dynasty. There's no concrete evidence suggesting that Muhammad-bin-Tughlaq temporarily lost territory in the northwest to the Mongols.

Hence, only statement 2 is correct.