Four girls decided to use the same teeter-totter. Two of them weighing 75 pounds and 50 pounds, respectively, sat on opposite ends of the 12-foot board which had the balance point at the center. The third girl weighting 60 pounds got on the same side as the one weighing 50 pounds and sat 5 feet from the fulcrum. Where must the fourth girl sit so the teeter-totter is balanced if she weighs 40 pounds?

i don't know i don't know

b) yes

step-by-step explanation:

let the statements be named as,

statement 1: if the power has been cut, then the refrigerator does not work.

statement 2: the refrigerator does not work.

conclusion: the power has been cut

now, 'law of detachment states that if we have the statements given as,

1. if p, then q.

2. p

then, we get the true statement or conclusion as q'.

thus, on comparing, we get that,

p: if the power has been cut.

q: the refrigerator does not work.

so, the argument is true by the law of detachment.