Advertisements
Advertisements
प्रश्न
Explain why 3 × 5 × 7 + 7 is a composite number.
Advertisements
उत्तर
We have, 3 × 5 × 7 + 7 = 7[3 × 5 + 1],
Which is not a prime number because it has a factor 7,
i.e. it has more than two factors.
Hence, it is a composite number.
APPEARS IN
संबंधित प्रश्न
Express the number as a product of its prime factor:
140
Check whether 6n can end with the digit 0 for any natural number n.
Find the least number that is divisible by the first ten natural numbers
Express 98 as a product of its primes.
For some integer p, every even integer is of the form ______.
The largest number which divides 60 and 75, leaving remainders 8 and 10 respectively, is ______.
According to the fundamental theorem of arithmetic, if T (a prime number) divides b2, b > 0, then ______.
The ratio of LCM and HCF of the least composite and the least prime numbers is ______.
If LCM(x, 18) = 36 and HCF(x, 18) = 2, then x is ______.
For some integer m, every even integer is of the form ______.
n2 – 1 is divisible by 8, if n is ______.
Can two numbers have 18 as their HCF and 380 as their LCM? Give reasons.
Two numbers are in the ratio 2 : 3 and their LCM is 180. What is the HCF of these numbers?
Assertion (A): The HCF of two numbers is 5 and their product is 150. Then their LCM is 40.
Reason(R): For any two positive integers a and b, HCF (a, b) × LCM (a, b) = a × b.
The prime factorisation of the number 2304 is ______.
If two positive integers a and b are written as a = x3y2 and b = xy3, where x, y are prime numbers, then the result obtained by dividing the product of the positive integers by the LCM (a, b) is ______.
National Art convention got registrations from students from all parts of the country, of which 60 are interested in music, 84 are interested in dance and 108 students are interested in handicrafts. For optimum cultural exchange, organisers wish to keep them in minimum number of groups such that each group consists of students interested in the same artform and the number of students in each group is the same. Find the number of students in each group. Find the number of groups in each art form. How many rooms are required if each group will be allotted a room?
Three bells toll at intervals of 9, 12 and 15 minutes respectively. If they start tolling together, after what time will they next toll together?
The HCF of two numbers 65 and 104 is 13. If LCM of 65 and 104 is 40x, then the value of x is ______.
