HCF & LCM, General Mathematics

Question: `444/629` when express is lowest terms is: `x^2`
A`13/37`

B`11/17`

C`11/19`

D`12/17`

Note: H.C.F. of 444 and 629 is 37
On dividing Nr & Dr by 37, we get `444/629=12/17`

Report

Question: The H.C.F. of `2^2 xx 3^3 xx 5^5` , `2^3 xx 3^2 xx 5^2 xx 7` and `2^4 xx 3^4 xx 5 xx 7^2 xx 11` is ___
A`2^2 xx 3^2 xx 5 xx 7 xx 11`

B`2^4 xx 3^4 xx 5^5`

C`2^4 xx 3^4 xx 5^5 xx 7 xx 11`

D`2^2 xx 3^2 xx 5`

Note: H.C.F. = product of lowest powers of common factors
       = `2^2 xx 3^3 xx 5`

Report

Question: The H.C.F. of `2^4 xx 3^2 xx 5^3 xx 7` , `2^3 xx 3^3 xx 5^2 xx 7^2` and `3 xx 5 xx 7 xx 11` is:
A105

B27720

C1155

D2310

Note: H.C.F.= product of lowest powers of common factors
         = `3 xx 5 xx 7= 105`

Report

Question: The H.C.F of 1095 and 3239 is :.
A37

B73

C43

D83

Note: Solution:
1095)  1168  (1
           1095
        -------------
               73)   1095     (15
                           73
                   ---------------
                               365
                               365
                    ---------------
                              `xx`

`:.` H.C.F=73

Report

Question: The H.C.F. of 2923 and 3239 is :
A37

B47

C73

D79

Note: solution:
2923) 3239 (1
      2923
       ---------
          316)   2923 (9
                 2844
                   --------
                       79)    316   (4
                              316   
                               -------
                                 `xx`


`:.` H.C.F.=79.

Report

Question: The H.C.F of 3556 and 3444 is :
A25

B26

C28

D23

Note: solution:
3444)    3556   (1 
             3444   
            --------
             112)      3444    (30
                          3360
                        ----------
                             84)   112   (1
                                       84
                                    --------
                                        28)    84   (3
                                                 84
                                               -------
                                                 `xx`

    `:.`H.C.F.=28

Report

Question: The H.C.F. of 210, 385 and 735 is :
A7

B14

C21

D35

Note: solution:
210=`2 xx 3 xx 5 xx 7`, 385=`5 xx 7 xx 11` & 735=`3 xx 5 xx 7^2`.

`:.`H.C.F.=`5 xx 7`=35.

Report

Question: Which of the following is a pair of co-primes ?
A(21, 35)

B(23, 92)

C(18, 25)

D(16, 62)

Note: solution:
H.C.F.of 18 and 25 is 1. So, they are co-primes.

Report

Question: The H.C.F. of `2/3 ,8/9,64/81 and 10/27` is :
A`2/3`

B`2/81`

C`160/3`

D`63/700`

Note: solution:
H.C.F.=`text(H.C.F. of 2,8,64,10)/text(L.C.M. of 3,9,81,27)` =`2/81`.

Report

Question: The H.C.F. of `9/10`,`12/25`,`18/35`and `21/40` is :
A`3/5`

B`252/5`

C`3/1800`

D`63/700`

Note: solution
H.C.F. =`(H.C.F. of 9,12,18,21)/(L.C.M. of 10,25,35,40)`=`3/2800`

Report