All digits are significant in this case. Any digit after a decimal point is a significant digit.
Three of them
There are four of them
3 in A+
All of the digits are significant:Any digit after the decimal point is significant.A zero is significant if it comes between other significant digits.
It has 4. Every 0 after a decimal and after a significant digit is significant.
There is one significant digit in the number 10, as written.
Every digit in 40.725 is significant, so there are 5
Two. The decimal indicates that the zero is significant otherwise it wouldn't be a significant digit.
The digit 90 has only one applicable significant figure.
One of them.