On her way home from work, Sandra fills up her car. She likes the idea of using gasoline with ethanol, but thinks her car can only handle 30% ethanol. At the gas station, she can use regular gas with 10% ethanol or E70 fuel with 70% ethanol. How many gallons of each type of fuel should Sandra use if she wants to fill up her car with 9 gallons of fuel containing 30% ethanol?

50 min

step-by-step explanation:

they will be decreasing both their times in half

60 / 2 = 30

40/2 = 20

30 + 20 = 50

£56

step-by-step explanation:

u divide 24 by 3 and u get 8 so if u do 8 time 7 or 8+8+8+8+8+8+8 u get 56 and 56 divided by 7 is 8.

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40