melguy wrote:
Hello
I am a newbie brushing up my basics on Quant. Please help. I am a bit confused with the method the bench mark values used by MGMAT guide 2. In the problem set Chapter 2 Q10
Put these fractions from the least to the greatest
9/17 , 3/6, 19/20 , 7/15
Explanation
9/17 is slightly more than 1/2
3/16 is slightly less than 1/4
19/20 is slightly less than 1
7/15 is slightly less than 1/2.
I am a bit confused with the language. For example how is 3/16 is slightly less than 1/4.
3 x 5 = 15
3 x 6 = 18
so it should fall between 1/5 and 1/6 hence it should be more than 1/4 not less (if i make any sense!)
Same with all the fractions. The language is exactly opposite what i expected it to be.
Please help clarify.
Another approach can be:
9/17 , 3/6, 19/20 , 7/15
Separate 3/6, 19/20 , 7/15 from 9/17
We see that 60 is the lcm for 6,20,15.
3/6, 19/20 , 7/15
Numerators will be: 30, 57, 28
Thus, 7/15 is the least among 3/6,19/20,7/15.
Now;
compare 9/17 with 7/15
7/15(less than 7/14=1/2) is less than 9/17(more than 9/18=1/2) and least among the choices.
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7/14=1/2
If the numerator(7) is kept constant:
Increase in denominator will decrease the value of the fraction.
Decrease in denominator will increase the value of the fraction.
If the denominator(14) is kept constant:
Increase in numerator will increase the value of the fraction.
Decrease in numerator will decrease the value of the fraction.
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_________________
~fluke
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