Answer:
Una persona necesitará 2 horas y 30 minutos de viaje en bicicleta para quemar el contenido kilocalórico de cinco galletas.
Step-by-step explanation:
De acuerdo con este problema, la cantidad de calorías que se quema es directamente proporcional al tiempo de viaje en bicicleta. Si sabemos que una galleta aporta 150 kilocalorías, entonces 5 galletas equivalen a 750 kilocalorías.
Por regla de tres simple calculamos el tiempo requerido para quemar 750 kilocalorías:


Es decir, una persona necesitará 2 horas y 30 minutos de viaje en bicicleta para quemar el contenido kilocalórico de cinco galletas.
Answer:
(D) Each year,the machinery loses a value of 4,500
When it is 3 years old,it is worth a little over 35K ,and when it is 6 years old,its worth about 22K.
This info means A,C and B is wrong b/c it loses too little value per year.
We're going to be using combination since this question is asking how many different combinations of 10 people can be selected from a set of 23.
We would only use permutation if the order of the people in the committee mattered, which it seems it doesn't.
Formula for combination:

Where
represents the number of objects/people in the set and
represents the number of objects/people being chosen from the set
There are 23 people in the set and 10 people being chosen from the set


Usually I would prefer solving such fractions by hand instead of a calculator, but factorials can result in large numbers and there is too much multiplication. Using a calculator, we get

Thus, there are 1,144,066 different 10 person committees that can be selected from a pool of 23 people. Let me know if you need any clarifications, thanks!
~ Padoru