3 sig figs.
There are four significant digits in the number 6.741.
4
It has 3 significant digits.
3 significant digits.
It has two significant digits.
Five. All nonzero digits are significant and zeros in between significant digits are significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Count the significant digits in each of the factors, and take the smallest of them.
Three significant digits.
50.4 has 3 significant digits.