GED Math Practice Test: Ratios, Percents and Geometry

$4.86 ÷ 18 = $0.27 per ounce and $6.24 ÷ 24 = $0.26 per ounce, so the larger box is cheaper by one cent per ounce. Comparing only the total prices makes the smaller box look like the better deal.

Sand is 2 parts, so one part is 9 ÷ 2 = 4.5 cubic feet, and gravel is 3 parts: 3 × 4.5 = 13.5 cubic feet. The value 27 is the total volume of all six parts, and 4.5 is the amount of cement.

I = 2,400 × 0.035 × 4 = $336. The amount $84 is only one year of interest, and $2,736 is the balance after 4 years (principal plus interest), not the interest itself.

The decrease is $80 − $68 = $12, and percent change is measured from the original price: 12 ÷ 80 = 0.15 = 15%. Dividing by the new price gives 12 ÷ 68 ≈ 17.6%, and 85% is the new price as a percent of the old one.

The sale price is 80% of the original, so the original is $56 ÷ 0.80 = $70. Adding 20% of $56 gives $67.20, which is wrong because the discount was 20% of the original price, not of the sale price.

Commission = 0.04 × sales, so sales = $1,380 ÷ 0.04 = $34,500. The value $5,520 comes from multiplying 1,380 by 4 instead of dividing by 0.04.

6 minutes is 360 seconds, which is 360 ÷ 45 = 8 groups of 45 seconds, so the printer makes 8 × 18 = 144 pages. Multiplying 18 by 6 gives 108, but that treats 45 seconds as if it were one minute.

Each inch on the plan is 4 feet, so the room is 3.5 × 4 = 14 feet by 4.25 × 4 = 17 feet, and its area is 14 × 17 = 238 square feet. Multiplying the plan area by 4 only once gives 59.5, and 62 is the perimeter in feet.

Edging goes around the circle, so you need the circumference: C = πd = 3.14 × 14 = 43.96 feet. The value 153.86 is the area (π × 7²), and 21.98 uses the radius in place of the diameter in C = πd.

Subtract the missing corner from the full rectangle: 20 × 12 − 6 × 4 = 240 − 24 = 216 square feet. Adding the corner instead gives 264, and 64 is the perimeter, which does not change when a corner is cut out this way.

The volume is 30 × 12 × 16 = 5,760 cubic inches, and 5,760 ÷ 231 ≈ 24.9, or about 25 gallons. An answer of 250 would require ten times the volume, so it comes from a misplaced decimal point.

V = 13 × π × 3² × 2 = 6π ≈ 18.8 cubic meters. Leaving out the 13 gives 56.5 (the volume of a cylinder), and using the diameter 6 as the radius gives 75.4.

Surface area = 2(10 × 8 + 10 × 5 + 8 × 5) = 2(80 + 50 + 40) = 340 square inches. The value 400 is the volume, 170 counts each pair of faces only once, and 260 leaves out the top.

The diagonal is √(240² + 100²) = √67,600 = 260 meters, and the walk along two sides is 240 + 100 = 340 meters, so the diagonal saves 340 − 260 = 80 meters. The value 260 is the length of the diagonal itself, not the savings.

The short side grows by a factor of 10 ÷ 4 = 2.5, so the long side becomes 6 × 2.5 = 15 inches. Adding the same 6 inches to each side gives 12, which changes the shape of the photo.