21. Una caja tiene 60 bombones. Eva se comió \( \frac{1}{5} \) de la caja y Ana \( \frac{1}{2} \). ¿Qué fracción de bombones queda? A) \( \frac{3}{10} \) B) \( \frac{5}{10} \) C) \( \frac{3}{10} \)

Carry out the calculations each person is performing and give the correct uncertainty. a) A truck operator estimates the distance from a land fill site to a job site to be 9.4 km . He adds 0.5 km for travel inside the job site and 0.3 km at the land fill site. What are the combined distances and uncertainties?

\( 2 + ( - \frac { 11 } { 3 } ) ; \quad - \frac { 1 } { 4 } - ( - \frac { 5 } { 6 } ) - 3 \)

The original price of a tablet was \( \$ 550 \). During a sale, Melvin was given a \( 30 \% \) discount for the tablet. How much did he pay for the tablet?

The length of a piece of ribbon is 250 millimeters. Which is the equivalent length in meters? \[ \begin{array}{l}\text { A. } 25 \mathrm{~m} \\ \text { D. } 2.5 \mathrm{~m} \\ 0.25 \mathrm{~m}\end{array} .025 \mathrm{~m} \] E. 0.0025 m

11. State the temperature shown on the thermometer in the form: measurement \( \pm \) uncertainty 12. The uncertainty for the speedometer of a vehicle is \( 5 \% \) of the speedometer's reading. Calculate the minimum speed a vehicle could be travelling if its speedometer reads 60