How to calculate easy when adding 1 to n?

Ageologist had two rocks on a scale that weighed 4.6 kilograms together.rock a was 0.5 of the total weight.how much did rock a weigh?

Which is a logical conclusion based on the given information? a. figure abcd is a rhombus by the definition of a rhombus. b. segment ac is congruent to segment dc by cpctc. c. angle acb is congruent to angle adc by the angle-side-angle theorem. d. triangle acd is congruent to triangle cab by the hypotenuse-leg theorem.

What 620000 divided by 10 to the third power