Using Euclid’s di

First using Euclid’s division algorithm for 84 and 144

We get, 144 = 84 × 1 + 60

84 = 60 × 1 + 24

60 = 24 × 2 + 12

24 = 12 × 2 + 0

Now, the remainder is zero, HCF of 84 and 144 is 12.

Now, 400 = 12 × 33 + 4

12 = 4 × 3 + 0

Now, remainder is zero, HCF of 400 and 12 is 4.

Hence, the HCF of 84, 144, and 400 is 4.