LCM and HCF
-  The least number, which when divided by 12, 15, 20 or 54 leaves a remainder of 4 in each case, is :
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                        View Hint View Answer Discuss in Forum Here , Remainder ( r ) = 4 
 As we know that When a number is divided by a, b , c or d leaving same remainder ‘r’ in each case then that number must be k + r where k is LCM of a, b , c and d.
 So , LCM of 15, 12, 20, 54 ( k ) = 540Correct Option: DHere , Remainder ( r ) = 4 
 As we know that When a number is divided by a, b , c or d leaving same remainder ‘r’ in each case then that number must be k + r where k is LCM of a, b , c and d.
 So , LCM of 15, 12, 20, 54 ( k ) = 540
 Hence , Then number = k + r = 540 + 4 = 544
-  The least number which when divided by 4, 6, 8, 12 and 16 leaves a remainder of 2 in each case is :
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                        View Hint View Answer Discuss in Forum Here , Remainder ( r ) = 2 
 As we know that When a number is divided by a, b , c or d leaving same remainder ‘r’ in each case then that number must be k + r where k is LCM of a, b , c and d.
 So , L.C.M. of 4, 6, 8, 12 and 16 = k = 48Correct Option: CHere , Remainder ( r ) = 2 
 As we know that When a number is divided by a, b , c or d leaving same remainder ‘r’ in each case then that number must be k + r where k is LCM of a, b , c and d.
 So , L.C.M. of 4, 6, 8, 12 and 16 = k = 48
 ∴ Required number = k + r = 48 + 2 = 50
-  The H.C.F. and L.C.M. of two numbers are 44 and 264 respectively. If the first number is divided by 2, the quotient is 44. The other number is
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                        View Hint View Answer Discuss in Forum Given , The H.C.F. and L.C.M. of two numbers are 44 and 264 . 
 According to question ,
 First number = 2 × 44 = 88
 As we know that ,
 ∴ First number × Second number = H.C.F. × L.C.M.
 ⇒ 88 × Second number = 44 × 264Correct Option: CGiven , The H.C.F. and L.C.M. of two numbers are 44 and 264 . 
 According to question ,
 First number = 2 × 44 = 88
 As we know that ,
 ∴ First number × Second number = H.C.F. × L.C.M.
 ⇒ 88 × Second number = 44 × 264⇒ Second number = 44 × 264 = 132 88 
-  The L.C.M. of three different numbers is 120. Which of the following cannot be their H.C.F.?
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                        View Hint View Answer Discuss in Forum Given that , The L.C.M. of three different numbers is 120. 
 LCM = 2 × 2 × 2 × 3 × 5
 Hence, HCF = 4, 8, 12 or 24Correct Option: DLCM = 2 × 2 × 2 × 3 × 5 
 Hence, HCF = 4, 8, 12 or 24
 According to question ,
 35 cannot be H.C.F. of 120.
 Hence , required answer is 35.
-  The HCF of two numbers is 23 and the other two factors of their LCM are 13 and 14. The larger of the two numbers is :
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                        View Hint View Answer Discuss in Forum Let the numbers be 23p and 23q .where p and q are co-prime. 
 ∴ LCM = 23pq
 According to question ,
 23pq = 23 × 13 × 14
 ∴ p = 13, q = 14Correct Option: ELet the numbers be 23p and 23q .where p and q are co-prime. 
 ∴ LCM = 23pq
 According to question ,
 23pq = 23 × 13 × 14
 ∴ p = 13, q = 14
 ∴ The larger number = 23q = 23 × 14 = 322
 
	