LCM and HCF
-  Two numbers are in the ratio 3 : 4. Their L.C.M. is 84. The greater number is
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                        View Hint View Answer Discuss in Forum Let the numbers be 3p and 4p. 
 ∴ Their LCM = 12p
 ∴ 12p = 84⇒ p = 84 = 7 12 
 Correct Option: CLet the numbers be 3p and 4p. 
 ∴ Their LCM = 12p
 ∴ 12p = 84⇒ p = 84 = 7 12 
 ∴ Larger number = 4p = 4 × 7 = 28
-  Two numbers are in the ratio 3 : 4. If their LCM is 240, the smaller of the two number is
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                        View Hint View Answer Discuss in Forum Let the number be 3p and 4p. Their LCM = 12p 
 According to the question,
 12p = 240⇒ p = 240 = 20 12 
 Correct Option: CLet the number be 3p and 4p. Their LCM = 12p 
 According to the question,
 12p = 240⇒ p = 240 = 20 12 
 ∴ Smaller number = 3p = 3 × 20 = 60
-  Three numbers are in the ratio 2 : 3 : 4 and their H.C.F. is 12. The L.C.M. of the numbers is
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                        View Hint View Answer Discuss in Forum Let the numbers be 2p, 3p and 4p respectively. 
 ∴ HCF = p = 12
 ∴ Numbers are : 2 × 12 = 24 , 3 × 12 = 36, 4 × 12 = 48
 LCM of 24, 36, 48 = 2 × 2 × 2 × 3 × 3 × 2Correct Option: ALet the numbers be 2p, 3p and 4p respectively. 
 ∴ HCF = p = 12
 ∴ Numbers are : 2 × 12 = 24 , 3 × 12 = 36, 4 × 12 = 48
 LCM of 24, 36, 48 = 2 × 2 × 2 × 3 × 3 × 2 = 144
-  The ratio of two numbers is 4 : 5 and their L.C.M. is 120. The numbers are
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                        View Hint View Answer Discuss in Forum Suppose the numbers are 4p and 5p respectively 
 According to question
 p × 4 × 5 = 120
 ⇒ p = 6Correct Option: CSuppose the numbers are 4p and 5p respectively 
 According to question
 p × 4 × 5 = 120
 ⇒ p = 6
 ∴ Required numbers = 4p = 4 × 6 = 24 and = 5p = 5 × 6 = 30
-  If the ratio of two numbers is 2 : 3 and their L.C.M. is 54, then the sum of the two numbers is
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                        View Hint View Answer Discuss in Forum Let the two numbers are 2p and 3p respectively. 
 According to question,
 LCM = 54
 ⇒ p ( 3 × 2 ) = 54
 ⇒ p = 9
 Numbers = 2p = 2 × 9 = 18 and, 3p = 3 × 9 = 27Correct Option: CLet the two numbers are 2p and 3p respectively. 
 According to question,
 LCM = 54
 ⇒ p ( 3 × 2 ) = 54
 ⇒ p = 9
 Numbers = 2p = 2 × 9 = 18 and, 3p = 3 × 9 = 27
 Sum of the two numbers = 18 + 27 = 45
 
	