1. (i) Here, 225 > 135

Applying Euclid’s division lemma to 225 and 135, we get

225 = (135 × 1) + 90

Since, 90 ≠ 0, therefore, applying Euclid’s division lemma

to 135 and 90, we get

135 = (90 × 1) + 45

Since, 45 ≠ 0

Applying Euclid’s division lemma to 90 and 45,

we get 90 = (45 × 2) + 0

Here, remainder, r = 0, when divisor is 45.

HCF of 225 and 135 is 45.

(ii) Here, 38220 > 196

Applying Euclid’s division lemma, we get

38220 = (196 × 195) + 0

Here, r = 0, when divisor is 196.

HCF of 38220 and 196 is 196.

(iii) Here, 867 > 255

Applying Euclid’s division lemma, we get

867 = (255 × 3) + 102,

255 = (102 × 2) + 51,

102 = (51× 2) + 0

Here remainder = 0, when divisor is 51.

HCF of 867 and 255 is 51.