Math Skills Test (MST)
The Math Skills Test is a timed, no-calculator section covering arithmetic, algebra, and geometry at roughly high-school level. The concepts you must have cold: order of operations; fraction, decimal, and percent conversions; ratio and proportion; exponent rules, including negative and zero exponents; solving linear equations and inequalities; systems of two equations; factoring quadratics; distance-rate-time, work-rate, and mixture problems; averages; and basic probability. Geometry includes angles on a line and inside triangles, similar triangles, the Pythagorean theorem, 30-60-90 and 45-45-90 triangles, perimeter, area, circumference, and the volume of boxes and cylinders.
Traps that show up
Percent increase versus percent of; unit mismatches (minutes versus hours, inches versus feet); answer choices built from the most common wrong operation; assuming a described figure is drawn to scale; dropping a negative sign when distributing; and rounding in the middle of a problem instead of at the end.
Rule of thumb and worked example
A 20 percent increase followed by a 20 percent decrease does not return you to the original price: multiply 1.20 x 0.80 = 0.96, a net 4 percent loss. Worked example: a machine stamps 18 parts in 4 minutes; at that rate, in 14 minutes it stamps 18 x (14/4) = 63 parts. Always reduce the problem to a per-unit rate first, then scale it. Because there is no penalty for a wrong answer on a timed test, eliminate two choices, estimate, and move on.