JEE Main 2021 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 25 July 2021, Shift 1, Maths Q88

Question 88 of 90 in this shift, Maths question 28 of 30, Section B.

Let

M=\left\{A=\begin{pmatrix}a&b\\c&d\end{pmatrix}:a,b,c,d\in\{\pm3,\pm2,\pm1,0\}\right\}

. Define

f:M\to\mathbf{Z}

, as

f(A)=\det(A)

, for all

A\in M

, where

\mathbf{Z}

is set of all integers. Then the number of

A\in M

such that

f(A)=15

is equal to _________.

Official answer

NTA final key.