Hell yeah, solution like this is wrong:

def check_ages?(data, sex, age_is_greater_than)
  data.all? { |i| i[:sex] == sex || i[:age] > age_is_greater_than }
end

check_ages?([{:age=>40, :sex=>:m}, {:age=>19, :sex=>:m}], :m, 20) will return true instead false

TIL f.(...) == f.call(...)

TIL f.(...) is an option. I always use f[...]

Ha, didn't know about this. Great solution!

That's why I got it wrong, it needs ALL matched sex to have a superior number!

Incorrectly converts THE-STEALTH-WARRIOR into THESTEALTHWARRIOR instead of into TheStealthWarrior

The task says returns true if all of the items matching the sex value have ages greater than the value provided.

I think the solution in question passes this.

What if all data contain only sex: 'f' and method run with sex: 'm', I think it be wrong.

this is neat :)

Great solution!

Seems matrixMultiplication is still used in default examples that are used when clicking "test" button