Explanation :
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
The rule apply for the addition and subtraction is :
The least precise number present after the decimal point determines the number of significant figures in the answer.
(a) 628 × 342

The correct answer is,

(b) (5363 × 102) × (7.4 × 103)

The correct answer is,

(c) 28.0 ÷ 13.483

The correct answer is, 2.08
(d) 8119 × 0.000023

The correct answer is,

(e) 14.98 + 27,340 + 84.7593

The correct answer is,

(f) 42.7 + 0.259

The correct answer is,
