9514 1404 393
Answer:
- 100 mL of 75% solution
- 150 mL of pure alcohol
Step-by-step explanation:
Let x represent the quantity (in mL) of pure alcohol needed for the mix. Then the amount of 75% needed is (250-x). The amount of alcohol in the mixture is ...
1.00x +0.75(250 -x) = 0.90(250)
0.25x +187.5 = 225 . . simplify
0.25x = 37.5 . . . . . . . . subtract 187.5
x = 150 . . . . . . . . . . . . . divide by 0.25
(250 -x) = 100 . . . . mL of 75% solution
You need 100 mL of the 75% solution and 150 mL of pure alcohol to obtain the desired mixture.
Answer:
508
Step-by-step explanation:
28*16= 448
6*6= 36
4*6= 24
448+36+24= 508
Answer:
Step-by-step explanation:
This is simply a units conversion problem. It gives us for the number of passengers, the number of seats per carriage and the number of carriages per train. To change the units from passengers to trains without changing the value, we use the multiplicative identity (that is, 1).
350000 passengers
(350000 passengers) * 1
(350000 passengers) * ((1 carriage)/(32 passengers)) * ((1 train)/(15 carriages)
[note: passengers and carriages cancel. Leaving only trains]
(350000)*(1/32)*(1/15) trains [note: I write this way to paste into MS Excel]
729.1667 trains [oh, but don’t just round this number either up or down]
729 full trains can carry 729*32*15 = 349920 passengers
730 full trains can carry 730*32*15 = 350400 passengers
Now, we can say that 730 trains are adequate to carry 350000 passengers.
Answer: C)
Step-by-step explanation: