Concept : 1 Mark
Calculation : 2 Marks
Conclusion : 1 Mark
Clearly, the required number is the HCF of the numbers
398 - 7 = 391, 436 - 11 = 425, and 542 - 15 = 527
First we find the HCF of 391 and 425 by Euclid's algorithm as given below
425 = 391 × 1 + 34
Here remainder is not zero. So applying Euclid's algorithm for 391 and 34
391 = 34 × 11 + 17
Here remainder is not zero. So applying Euclid's algorithm for 34 and 17
34 = 17 × 2 + 0
Here the remainder is zero.
Clearly, H.C.F of 391 and 425 is 17.
Let us now find the HCF of 17 and the third number 527 by Euclid's algorithm:
527 = 17 × 31 + 0
Here the remainder is zero.
The HCF of 17 and 527 is 17. Hence, HCF of 391, 4250 and 527 is 17.
Hence, the required number is 17.