Ratios and Rates

Estimate how far apart Greenreach and Secluded City are, based on this map of Damriel.

• 75 km

• 100 km

• 125 km

• 150 km

When making bread dough, a baker needs to know what the “hydration” of the dough is. “Hydration” is the ratio of water to flour, by weight.

A recipe has 300 grams of water, and 500 grams of flour. What would be the hydration of this dough, as its simplest form?

• 1 : 1.667

• 3 : 8

• 300 : 800

• 3 : 5

I want to make a simple salad dressing. Google says to use three parts oil to one part vinegar. How much oil and vinegar do I need if I want 240 mL of salad dressing?

• 180 mL oil, 60 mL vinegar

• 60 mL oil, 180 mL vinegar

• 160 mL oil, 80 mL vinegar

• 80 mL oil, 160 mL vinegar

I pour myself 40 mL of concentrated cordial. The cordial needs to be diluted in a 1 : 4 ratio of concentrate : water. How much water do I need to add?

• 8 mL

• 10 mL
  

• 160 mL
  

• 200 mL
  

Ethelbert worked a four hour shift and earned $53.56. What is his pay rate? Enter your answer as $[...]/hr, to the nearest cent.

Fuel is 117.9 ¢/L at a petrol station. It cost $61.31 to fill up my car from completely empty. How big is my fuel tank, to the nearest litre?

• 2 L

• 72 L

• 52 L

• 62 L

The Earth travels at 29.78 km/s (!) around the Sun. Find out how far it travels in a minute.

A basketball court is 28.7 m long. How many basketball court lengths does the Earth travel in an minute? (Hint: use what you calculated above.)

• 62

• 622

• 6,225

• 62,258

If I take 39 minutes to drive 42 km, what is my average speed in kilometres per hour? Write as [...] km/h, to the nearest whole number.

Taylor and Norma get their water bill and see that they use, on average, 471 L/day of water. Assuming they keep using water at the same rate, how much water would they use in a (non-leap) year?

• 1.72 kL

• 17.2 kL

• 172 kL

• 1720 kL

The European swallow has an average airspeed of about 40 km/hr. If Tim the swallow traveled 1,300 km south for the winter, how long would his trip take? Assume he doesn't take a break. (Put in your answer as [...] hours, and round to the nearest hour.)