If 57=x(mod 4), what is the least positive value of x?

The correct answer is option (2) : 1

Given $57 = x(mod\, 4)$

$57-x$ is divisible by 4.

$57-x$ is a multiple of 4

$57-x= 4\lambda, \lambda \in I$

$x= 57- 4\lambda $

Put $\lambda = 14 $

$x= 57 - 4×14=1$

$\lambda = 15 $

$x= 57 - 4 × 15 = -3$

∴ Least +ve value of $x = 1$