Aptitude - Problems on H.C.F and L.C.M - Discussion
Discussion Forum : Problems on H.C.F and L.C.M - General Questions (Q.No. 24)
24.
Which of the following fraction is the largest ?
Answer: Option
Explanation:
L.C.M. of 8, 16, 40 and 80 = 80.
| 7 | = | 70 | ; | 13 | = | 65 | ; | 31 | = | 62 |
| 8 | 80 | 16 | 80 | 40 | 80 |
| Since, | 70 | > | 65 | > | 63 | > | 62 | , so | 7 | > | 13 | > | 63 | > | 31 |
| 80 | 80 | 80 | 80 | 8 | 16 | 80 | 40 |
| So, | 7 | is the largest. |
| 8 |
Discussion:
49 comments Page 1 of 5.
Manju said:
1 decade ago
Hai guys!
The following fractions are 7/8, 13/16, 31/40, 63/80.
If we take 7/8. First we have to sub these (8-7 =1 ) and divide numerator with 1 (7/1 = 7) same process.
13/16, 16-13 = 3 13/3 = 4.3.
31/40, 40-31 = 9 31/9 = 3.4.
63/80, 80-63 = 17 60/17 = 3.94.
By this we can easily say that 7, 4.3, 3.94, 3.4.
(this process we can applicable for descending and ascending order).
The following fractions are 7/8, 13/16, 31/40, 63/80.
If we take 7/8. First we have to sub these (8-7 =1 ) and divide numerator with 1 (7/1 = 7) same process.
13/16, 16-13 = 3 13/3 = 4.3.
31/40, 40-31 = 9 31/9 = 3.4.
63/80, 80-63 = 17 60/17 = 3.94.
By this we can easily say that 7, 4.3, 3.94, 3.4.
(this process we can applicable for descending and ascending order).
Yamini.p said:
1 decade ago
First compare the options from this multiply a&b.
Cross multiplication,
7/8x13/16 = 112,104,
So here 112 is highest so, 7/8 is highest.
Again comparison a&c.
7/8x31/40 = 280,240.
So here 280 is higher so, 7/8 is highest.
Again comparison a&d.
7/8x63/80 = 560,504.
So here 560 is higher so, 7/8 is highest.
The answer is 7/8 is the higher.
Cross multiplication,
7/8x13/16 = 112,104,
So here 112 is highest so, 7/8 is highest.
Again comparison a&c.
7/8x31/40 = 280,240.
So here 280 is higher so, 7/8 is highest.
Again comparison a&d.
7/8x63/80 = 560,504.
So here 560 is higher so, 7/8 is highest.
The answer is 7/8 is the higher.
Vaibhav said:
8 years ago
Hello, guys.
The lcm is 80. So we have to make 80 as the base for all numbers. In this example, if we want to make base 80 for no 7/8 we have to multiply the N and D by 10. For 13/16 for base 80-multiply N and D by 5. For 31/40 for making base 80 multiply N and D by 2. And 4rth no already has base 80 so we don't need anything to do.
The lcm is 80. So we have to make 80 as the base for all numbers. In this example, if we want to make base 80 for no 7/8 we have to multiply the N and D by 10. For 13/16 for base 80-multiply N and D by 5. For 31/40 for making base 80 multiply N and D by 2. And 4rth no already has base 80 so we don't need anything to do.
(2)
Amita said:
1 decade ago
(a) 7/8 (b) 13/16 (c) 31/40 (d) 63/80.
First of all I compare b/t a and b with cross multiplication.
7/8, 13/16.
7*16 13*8.
112 >104.
So 7/8>13/16.
Again compare b/t 7/8 and 31/40.
7*40 31*8.
280 > 248, so 7/8>31/40.
Again compare b/t 7/8 and 63/80.
7*80 8*63.
560 > 504, so 7/8>63/80.
So 7/8 is largest.
First of all I compare b/t a and b with cross multiplication.
7/8, 13/16.
7*16 13*8.
112 >104.
So 7/8>13/16.
Again compare b/t 7/8 and 31/40.
7*40 31*8.
280 > 248, so 7/8>31/40.
Again compare b/t 7/8 and 63/80.
7*80 8*63.
560 > 504, so 7/8>63/80.
So 7/8 is largest.
Mayur said:
4 years ago
First find LCM Of denominator;
LCM of 8,16,40,80=80
Now let's same all the denominator
7*10/8*10. = 70/80.
13*5/16*5. = 65/80.
31*2/40*2 62/80.
63*1/80*1. 63/80.
As u can see all the denominators is the same,
So see numerator now 70/80 { 70 is biggest}
Which means
7/8 Is the largest fraction.
LCM of 8,16,40,80=80
Now let's same all the denominator
7*10/8*10. = 70/80.
13*5/16*5. = 65/80.
31*2/40*2 62/80.
63*1/80*1. 63/80.
As u can see all the denominators is the same,
So see numerator now 70/80 { 70 is biggest}
Which means
7/8 Is the largest fraction.
(10)
Hanumanth said:
1 decade ago
The simple way to solve this type of problems is.
The difference between the numerator and denominator less than any of the given numbers is the largest value.
Ex:
7/8=1.
13/16=3.
31/40=9.
63/80=17.
Less difference is 1 so 7/8 is greater value.
The difference between the numerator and denominator less than any of the given numbers is the largest value.
Ex:
7/8=1.
13/16=3.
31/40=9.
63/80=17.
Less difference is 1 so 7/8 is greater value.
Sarah said:
9 years ago
LCM of 8, 16, 40 and 80 is 80 then,
80/8 = 10.
80/16 = 5.
80/40 = 2.
80/80 = 1 then,
7/8 * 10/10 = 70/80.
13/16 * 5/5 = 65/80.
31/40 * 2/2 = 62/80.
63/80 * 1 = 63/80.
70/80 > 65/80 >63/80 > 62/80.
So 7/8 is largest.
80/8 = 10.
80/16 = 5.
80/40 = 2.
80/80 = 1 then,
7/8 * 10/10 = 70/80.
13/16 * 5/5 = 65/80.
31/40 * 2/2 = 62/80.
63/80 * 1 = 63/80.
70/80 > 65/80 >63/80 > 62/80.
So 7/8 is largest.
(1)
Nizamuddin said:
1 decade ago
No Prashant. Vidya is not correct to find the answer. Because you have to calculate all the possible values to retreive the answer. This is long process too rather than the problem explained in the beginning.
Deepika said:
1 decade ago
@Archana
4,16,40,80
its simple yar first we have to check that 80 have multiples of 4,16,40
like 4*20,16*5,40*2,80*1.
So 80 is the correct lcm value check like this is is the easy way.
4,16,40,80
its simple yar first we have to check that 80 have multiples of 4,16,40
like 4*20,16*5,40*2,80*1.
So 80 is the correct lcm value check like this is is the easy way.
Power star pawan kalyan said:
1 decade ago
@Jyoti Mehta
We first find the lcm of the given numbers...7/8,13/16,31/40,63/80
then We'll get that value=80
So.. there goes the process and you'll get the above result...;)
We first find the lcm of the given numbers...7/8,13/16,31/40,63/80
then We'll get that value=80
So.. there goes the process and you'll get the above result...;)
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