Question

HCf of 840,1540,1680

Answer 1

I hope this may help you

Answer 2

PRIME factorisation of 840
840 = 2 × 2 × 2 × 3 × 5 × 7
PRIME factorisation of 1540
1540 = 2 × 2 × 5 × 7 × 11
PRIME factorisation of 1680
1680=2*2*2*2*3*5*7
To find the HCF, multiply all the prime factors common to both numbers:

Therefore, HCF=2*2*5*7=140

I hope it helps.