CHAPTER-1, REAL NUMBERS 1. If a= 3 x 5, b = 3 x 5^{2} and c 2^{5} x 5, then LCM (a, b, c) and HCF (a, b, c) are 2400, 15 2400, 5 1200, 5 1200, 15 2. The HCF of two consecutive integers is 2 4 1 0 3. The prime factorisation of q has 2 and 3 only and the HCF (q, 72) is 12. The number of value(s) q can takes is 4 3 2 1 4. For some integer m, every odd integer is of the form 2m + 1 2m m m + 1 5. If 3 is the least prime factor of p and 5 is the least prime factor of q, then the least prime factor of (p + q) is 2 3 11 5 6. Greatest number which divides 2011 and 2623 leaving remainders 9 and 5 respectively is 154 15 135 144 7. Between 1 and 3, how many rational numbers exists? 0 1 Infinitely many 2 8. If x and y are two rational numbers then x + y is neither rational nor irrational number either rational or irrational number a rational number an irrational number 9. For some integer q every even integer is of the form 2q + 1 2q q + 1 q 10. A circular field has circumference of 360 km Two cyclist Peter and John start together and can cycle at speeds of 12 km/h and 15 km/h respectively, round the circular field. The time take by them to meet again at the starting point is 180 hrs 150 hrs 130 hrs 120 hrs Loading … Question 1 of 10