If a = −3/4 and b = 5/6, then which of the following does not lie between a and b?

a = −3/4 = −0.75 and b = 5/6 ≈ 0.833. For a number to lie between them, it must be greater than −0.75 and less than 0.833. Check: 0 lies in this range. −1/2 = −0.5 lies in range. −2/5 = −0.4 lies in range. −7/9 ≈ −0.778, which is less than −0.75, so it does NOT lie between a and b. Hence the answer is −7/9.