JEE Main 2025 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 3 April 2025, Shift 1, Maths Q21

Question 21 of 75 in this shift, Maths question 21 of 25, Section B.

If the number of seven-digit numbers, such that the sum of their digits is even, is

m \cdot n \cdot 10^n

;

m, n \in \{1, 2, 3, \ldots, 9\}

, then

m + n

is equal to ______

Official answer

NTA final key.

Chapter: Permutations and Combinations
Topic: Permutations and Combinations
Idea tested: Fundamental Counting Principle

Same idea in other shifts

Asked 4× in all

8 Apr 2024, Shift 1 · Q23The number of 3-digit numbers, formed using the digits 2, 3, 4, 5 and 7, when the repetition of digits is not allowed, and which are not…MediumNumerical value
13 Apr 2023, Shift 2 · Q22Total numbers of 3-digit numbers that are divisible by 6 and can be formed by using the digits 1, 2, 3, 4, 5 with repetition, is ______MediumNumerical value
28 Jul 2022, Shift 1 · Q21Let S be the set of all passwords which are six to eight characters long, where each character is either an alphabet from $\{A,B,C,D,E\}$ …MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.