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The HCF of the numbers 310, 208 and 180 is:
2
4
6
8
2
Find the prime factorizations of all three numbers and determine the product of the lowest powers of common prime factors, or use division method. Note that all numbers are even, so 2 must be a common factor.
Three numbers are given: 310, 208, and 180.
HCF(a,b,c)=GCD(GCD(a,b),c)
Find the prime factorizations of all three numbers and determine the product of the lowest powers of common prime factors, or use division method. Note that all numbers are even, so 2 must be a common factor.
Students often find the LCM instead of the HCF, or make calculation errors during prime factorization.
Step 1: Prime Factorization of 310
Express 310 as a product of prime factors: 310=2├Ч155=2├Ч5├Ч31.
310=2├Ч5├Ч31
Step 2: Prime Factorization of 208
Express 208 as a product of prime factors: 208=2├Ч104=22├Ч52=23├Ч26=24├Ч13.
208=24├Ч13
Step 3: Prime Factorization of 180
Express 180 as a product of prime factors: 180=2├Ч90=22├Ч45=22├Ч32├Ч5.
180=22├Ч32├Ч5
Step 4: Determine HCF
Find the lowest power of common prime factors among 310, 208, and 180. The only common prime factor is 2, and its lowest exponent across all three numbers is 1. Thus, HCF=21=2.
HCF(310,208,180)=2
A is correct because the highest common factor of 310, 208, and 180 is 2.
Understanding prime factorization is also essential for simplifying fractions and solving LCM-HCF word problems efficiently in competitive exams.