To solve the problem of determining the sum of the masses with consideration to significant figures, we start by examining the given measurements:
Let's identify the number of decimal places in each of these measurements:
The measure with the least number of decimal places is 226.3 g, which has 1 decimal place. Hence, the final result of the addition needs to be rounded to 1 decimal place.
\[ 435.42 \, \text{g} + 226.3 \, \text{g} + 0.125 \, \text{g} = 661.845 \, \text{g} \]
The correct answer is therefore 661.8 g.
This option is correct due to applying the rule of least decimal places in addition, which is pivotal in handling significant figures in arithmetic operations.
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,

A vernier caliper has \(10\) main scale divisions coinciding with \(11\) vernier scale division equals \(5\) \(mm\). the least count of the device is :
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)