Can somebody plsss help me with these 2 questions

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?

Aculture started with 2,000 bacteria. after 8 hours, it grew to 2,400 bacteria. predict how many bacteria will be present after 19 hours . round your answer to the nearest whole number. p=ae^kt

The dash figure is a dilation if the original figure. find the scale factor. classify the dilation as an enlargement or a reduction