A cooler must keep water below 10 °C for 2 hours and use recycled material. Foam: 8 °C, new plastic; newspaper: 9 °C, recycled; cotton: 12 °C, recycled. Which design fits?

A bridge must hold at least 50 N using under 200 g of craft sticks. Arch: 60 N, 220 g; truss: 55 N, 180 g; beam: 45 N, 160 g. Which design qualifies?

Use the table comparing Filters A, B, and C. A filter must remove at least 80% of particles and cost no more than $5. Which filter best meets both?

A garden device must use 3 V and water soil only below 25% moisture. Timer: 5 V, 20%; sensor: 3 V, 20%; sponge: 3 V, 35%. Which solution meets both limits?

A solar cooker must heat 500 mL of water to at least 70 °C and cost under $12. Box: 72 °C, $10; cone: 80 °C, $18; flat panel: 60 °C, $8. Which should be chosen?

A slope barrier must reduce runoff at least 40% and install in under 30 minutes. Rock wall: 50%, 45 min; straw wattles: 42%, 25 min; grass seed: 35%, 20 min. Which solution fits?

A strap pad must keep pressure under 8 kPa and add under 60 g. Gel: 6 kPa, 90 g; foam: 7 kPa, 40 g; cloth: 9 kPa, 30 g. Which prototype meets both?

A package must keep a jar uncracked after a 1 m drop and use no plastic. Bubble wrap: works, plastic; shredded paper: works, paper; cloth: fails, plastic-free. Which meets both?

Water-filter goal: clearest water, under $40, flow at least 1 L/min. A: clarity 9, $55, 2 L/min. B: 8, $35, 1.5 L/min. C: 4, $30, 3 L/min. Which trade-off is best?

A turbine should maximize electricity while staying below 50 dB and $20. A: 7 W, 60 dB, $15. B: 6 W, 45 dB, $18. C: 4 W, 40 dB, $10. What trade-off is best?

A sanding mask should block the most dust with resistance under 30 Pa. X: 95%, 45 Pa. Y: 90%, 25 Pa. Z: 70%, 15 Pa. Which trade-off is best?

Rain barrel goal: store at least 100 L, pass 80 cm gate, minimize cost. A: 120 L, 90 cm, $35. B: 100 L, 75 cm, $50. C: 80 L, 60 cm, $25. Which trade-off works?

Phone case goal: survive 1 m drop, stay under 80 g, minimize thickness. A: survives, 12 mm, 70 g. B: survives, 8 mm, 90 g. C: cracks, 6 mm, 40 g. Which trade-off is best?

A greenhouse cover should maximize light and lose under 5 °C overnight. Clear: 90%, 8 °C. Bubble: 75%, 4 °C. Cloth: 50%, 3 °C. Which trade-off is best?

Use the table comparing windbreak models. The systematic process first eliminates designs over $15 or 30 minutes, then chooses highest strength. What conclusion follows?

The comparison table rates cup-sleeve materials. A fair process rejects any material over 100 g or $3, then compares insulation score. What conclusion follows?

Use the mosquito-trap table. The process eliminates prototypes above 5 W or 40 dB, then selects the highest capture rate. What conclusion is supported?

Use the helmet table. The class weights safety twice as much as comfort and sets a $30 cost limit. The table shows total weighted scores. What decision follows?

Use the tray-material table. A systematic process checks strength at least 4, water resistance at least 4, and cost no more than $0.20. What material passes all criteria?

Use the roof-prototype table. The process rejects designs over 2 kg or 20 minutes, then chooses greatest leak reduction. What conclusion follows?