Question

4.7 weeks = ____ minutes (round off based on sig figs)

Answer 1

We can calculate this using this equivalencies:

- 7 days per week

- 24 hours per day

- 60 minutes per hour

Then, we can calculate the number of minutes as:

`4.7\text{ weeks}\cdot7\frac{\text{ days}}{\text{ week}}\cdot24\frac{\text{ hours}}{\text{ day}}\cdot60\frac{\text{ minutes}}{\text{ hour}}=47,376\text{ minutes}`

Our precission in the weeks measure is 0.1 weeks (one decimal).

This is equivalent to 1,000 minutes (1 week = 10,000 minutes).

Then, if we express the minutes round off on ginificant figures of the original measure (0.1 weeks = 1,000 minutes), the answer is 47,000 minutes.

11) 165,800 cm = ____ Mm (Megametre)

We know that 1 Mm is 1,000,000 meters (one million metres), and that 1 meter is equal to 100 cm, so we can write the equivalencies as:

`165,800\text{ cm}\cdot\frac{1\text{ m}}{100\text{ cm}}\cdot\frac{1\text{ Mm}}{1,000,000\text{ m}}=\frac{165,800\text{ Mm}}{100\cdot1,000,000}=0.001658\text{ Mm}`

The anser is 0.001658 Mm.