model 2 find lcm of numbers Practice Questions Answers Test with Solutions & More Shortcuts
LCM & HCF PRACTICE TEST [5 - EXERCISES]
model 1 Basic formula of LCM & HCF
model 2 find lcm of numbers
model 3 find hcf of numbers
model 4 addition, subtraction, multiplication and division with lcm & hcf
model 5 lcm & hcf vs ratios
Question : 11 [SSC CGL Prelim 2004]
If the students of a class can be grouped exactly into 6 or 8 or 10, then the minimum number of students in the class must be
a) 240
b) 180
c) 120
d) 60
Answer »Answer: (c)
Required number of students = LCM of 6, 8, 10 = 120
Question : 12 [SSC CGL 2012]
The greatest number of four digits which when divided by 3, 5, 7, 9 leave remainders 1, 3, 5, 7 respectively is :
a) 9765
b) 9766
c) 9764
d) 9763
Answer »Answer: (d)
The difference between divisor and the corresponding remainder is equal.
LCM of 3, 5, 7 and 9 = 315 Largest 4-digit number = 9999
31$234/315$ = 9999
∴ Number divisible by 315 = 9999 – 234 = 9765
Required number = 9765 – 2 = 9763
Question : 13 [SSC CGL Prelim 2002]
Find the greatest number of five digits which when divided by 3, 5, 8, 12 have 2 as remainder :
a) 99962
b) 99960
c) 99958
d) 99999
Answer »Answer: (a)
Using Rule 4,
i.e. When a number is divided by x, y or z leaving same remainder ‘R’ in each case then that number must be K + R where k is LCM of x, y and z.
The greatest number of five digits is 99999.
LCM of 3, 5, 8 and 12
2 | 3, | 5, | 8, | 12 |
2 | 3, | 5, | 4, | 6 |
3 | 3, | 5, | 2, | 3 |
1, | 5, | 2, | 1 |
∴ LCM = 2 × 2 × 3 × 5 × 2 = 120 After dividing 99999 by 120, we get 39 as remainder 99999 – 39 = 99960 = (833 × 120)
99960 is the greatest five digit number divisible by the given divisors.
In order to get 2 as remainder in each case we will simply add 2 to 99960.
∴ Greatest number = 99960 + 2 = 99962
Question : 14 [SSC CGL Tier-II 2017]
Three electronic devices make a beep after every 48 seconds, 72 seconds and 108 seconds respectively. They beeped together at 10 a.m. The time when they will next make a beep together at the earliest is
a) 10 : 07 : 48 hours
b) 10 : 07 : 36 hours
c) 10 : 07 : 24 hours
d) 10 : 07 : 12 hours
Answer »Answer: (d)
Required time = LCM of 48, 72 and 108 seconds
2 | 48, | 72, | 108 |
2 | 24, | 36, | 54 |
2 | 12, | 18, | 54 |
3 | 6, | 9, | 27 |
3 | 2, | 3, | 9 |
2, | 1, | 3 |
∴ LCM = 2 × 2 × 2 × 2 × 3 × 3 × 3 = 432 seconds
= 7 minutes 12 second
∴ Required time = 10 : 07 : 12 hours
Question : 15
Which is the least number which when doubled will be exactly divisible by 12, 18, 21 and 30 ?
a) 196
b) 630
c) 1260
d) 2520
Answer »Answer: (b)
The LCM of 12, 18, 21, 30
2 | 12, | 18, | 21, | 30 |
3 | 6, | 9, | 21, | 15 |
2, | 3, | 7, | 5 |
∴LCM = 2 × 3 × 2 × 3 × 7 × 5 = 1260
∴ The required number
=$1260/2$ = 630
IMPORTANT quantitative aptitude EXERCISES
model 2 find lcm of numbers Shortcuts »
Click to Read...model 2 find lcm of numbers Online Quiz
Click to Start..LCM & HCF Shortcuts and Techniques with Examples
-
model 1 Basic formula of LCM & HCF
Defination & Shortcuts … -
model 2 find lcm of numbers
Defination & Shortcuts … -
model 3 find hcf of numbers
Defination & Shortcuts … -
model 4 addition, subtraction, multiplication and division with lcm & hcf
Defination & Shortcuts … -
model 5 lcm & hcf vs ratios
Defination & Shortcuts …
quantitative aptitude CATEGORIES
RECENT BLOGS
Recently Added Subject & Categories For All Competitive Exams
Most Important Antonyms Vocabulary - IBPS Clerk Prelims 2024
Latest Antonyms multiple choice questions and answers with free PDFfor IBPS Clerk Prelims 2024. English Vocabulary practice exercise for all bank exam
Continue Reading »
Syllogism Practice Questions Answers PDF - IBPS Clerk 2024
Practice Verbal Reasoning Syllogism multiple choice questions and answers with Fully solved explanation, PDF for the IBPS Clerk Prelims 2024 Bank Exam
Continue Reading »
IBPS Clerk Prelims 2024 Synonyms Questions Solved Answers
Most important IBPS Clerk Prelims 2024 Synonyms and Antonyms multiple choice questions and answers with detailed solutions, English vocabulary PDF Download
Continue Reading »
New Cloze Test Questions and Answers PDF - IBPS Clerk 2024
The most important Cloze Test questions with detailed answers for upcoming IBPS Clerk prelims 2024. Latest English verbal ability practice MCQs, PDF
Continue Reading »