First you need to divide 125 / 25 which is 5 then you do subtraction 21 x 5 which is 105, then you subtract again 125 - 105 which is 20, 20 light bulbs will be broken. Or you could have just multiplied 5 by 4 which is the amount of light bulbs that were broken which is a lot easier...
We have the following function: N (k): Where, the indepent variable is k The dependent variable is N For the function: k (n): the independent variable is n The dependent variable is k Thus, N (12) = 4 k (4) = 12 Answer: TRUE option A