3. Use Euclid’s division algorithm to find the HCF of 504 and 980. 4. Show that 5+3√2 is irrational. 5. Show that 3-2√5 is irrational. 6. Using Euclid’s division algorithm find the HCF of 231 and 396 7. The LCM and HCF of two numbers are 360 and 9 respectively. If one of the numbers is45 find the other number 8. Explain why 7 × 11 × 13 + 13 and 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 are composite numbers 9. If d is the HCF of 40 and 65, find the value of integers x and y which satisfy d = 40x + 65y. 10. Find the largest positive integer that will divide 398, 436 and 542 leaving remainders 7,11,15 respectively.