Question

500 million houses in 42 hours how many per minute

Answer 1

like a first step you need convert the 42 hours in minutes

do you know it how ?

Answer 2

so using the rule of 3 simple you can write - hope you now that 1 hour has 60 minutes

1 hour has 60 minutes
42 hours has x minutes and now cross multiplie so calcule the x value

x = 42*60/1 = 42*60 = ? minutes

than you get this result you need using again the rule of 3 simple and write

500 million houses in this get result of x minutes
1 house in y minutes so cross multiplie and calcule the y value

y = 1*x /500 million = x/500 million minutes

hope helped understandably easy