Question

um carro a 80 km por hora, quanto tempo vai demorar pra ele percorrer 50 km?

Answer 1

$\frac{\text{50 km}}{\text{80 km/h}} = \text{0,625 hora} \equiv \text{37,5 minutos} \equiv \text{37 minutos e 30 segundos}$

Answer 2

Realizando uma regra de 3 simples:

80 km - 60 min (1 hora)
50 km - k

$\mathsf{k=\dfrac{50\cdot 60}{80}}\\\\\\\mathsf{k=\dfrac{50\cdot 6}{8}}\\\\\\\mathsf{k=\dfrac{50\cdot 3}{4}}\\\\\\\mathsf{k=\dfrac{25\cdot 3}{2}}\\\\\\\mathsf{k=\dfrac{75}{2}}\\\\\\\boxed{\mathsf{k=37,5\:minutos=37\:minutos\:e\:30\:segundos}}\: \: \checkmark$