if y is inversely proportional to x and y = 41 when x = 10, what is the value of y when x =7?

You won’t see inverse proportionality on the current SAT, but in inverse proportions the *product* of the two numbers remains constant: . In this case, if when , then the product is 410: . Now you just need to solve:

(This would work out much cleaner if were equal to 42 in the beginning…)