SAT Math : How to find the ratio of a fraction
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Example Question #52 : Proportion / Ratio / Rate
A TV show lasts 30 minutes, what fraction of the show is left after 12 minutes have passed?
4/10
3/5
2/3
1/3
12/15
3/5
After watching 12 minutes of the show 18 remain. 18 is 60% of the total 30 minutes. As a fraction it can be expressed as 3/5.
Example Question #2 : How To Find The Ratio Of A Fraction
A bag contains red, orange, and yellow marbles only. The marbles occur in a ratio of 5 red marbles: 4 orange marbles: 1 yellow marble. If one-third of the red marbles, one-half of the orange marbles, and one-fourth of the yellow marbles are removed, then what fraction of the remaining marbles in the bag is red?
39/73
37/77
43/75
40/43
40/73
40/73
Example Question #1 : How To Find The Ratio Of A Fraction
Marty drove 40 mi/hr for 3 hours, then 60 mi/hr for 1 hour, and finally 70 mi/hr for the last 2 hours. What was Marty's average speed?
47 mi/hr
63 mi/hr
60 mi/hr
53 mi/hr
58 mi/hr
53 mi/hr
Marty's total driving time was 3 + 1 + 2 = 6 hours. He drove 40 mi/hr for 3 hours, or 3/6 = 1/2 of the time. He drove 60 mi/hr for 1 hour, or 1/6 of the drive. Lastly, he drove 70 mi/hr for 2 hours, or 2/6 = 1/3 of the drive.
To find the average speed, we need to multiply the speeds with their corresponding weights and add them up.
Average = 1/2 * 40 + 1/6 * 60 + 1/3 * 70 = 53.33... ≈ 53 mi/hr
Example Question #54 : Proportion / Ratio / Rate
A pie is made up of 
A pie is made up of 
To compute this ratio, you must first ascertain how much of the pie is jelly. This is:
Begin by using the common denominator 
So, the ratio of crust to jelly is:
This can be written as the fraction:
Example Question #55 : Proportion / Ratio / Rate
In a solution, 
This problem is really an easy fraction division. You should first divide the lemon juice amount by the water amount:
Remember, to divide fractions, you multiply by the reciprocal:
This is the same as saying:
Example Question #56 : Proportion / Ratio / Rate
If 
To find a ratio like this, you simply need to make the fraction that represents the division of the two values by each other. Therefore, we have:
Recall that division of fractions requires you to multiply by the reciprocal:
which is the same as:
This is the same as the ratio:
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