Question

a solution turns red litmus to blue, what is its ph value

Answer 1

It is a base therefore it's pH will be between 7.1 - 14

Answer 2

if solution turns red litmus blue,than it is base .hence its ph is more than 7.
according to ph measures if it turns red litmus blue than it"s is likely to be basic in nature .so it"s ph measures is regarded as between 7.1 to 14