Question

1) The two numbers are 25 and 60. If its LCM is 300. Find its HCF.
2) Find the LCM of the following : a) 25 and 35 b)60 and 90
3) Ramesh bought 54 mango and 74 orange candies. If he distributed them equally among the children find the maximum number of candies a child gets.
4) Find the lowest number which is exactly divisible by 18 and 24.
5) Find the HCF of the following : a) 15 and 18 b)20 and 40

Answer 1

Answer:

1. PRODUCT OF NUMBER=PRODUCT OF H.CF and LCM

Required number =

112

28×336 =84

2.Using prime factorisation method:

(i) 12, 15 and 21

Factor of 12=2×2×3

Factor of 15=3×5

Factor of 21=3×7

HCF (12,15,21)=3

LCM (12,15,21)=2×2×3×5×7=420

(ii) 17, 23 and 29

Factor of 17=1×17

Factor of 23=1×23

Factor of 29=1×29

HCF (17,23,29)=1

LCM (17,23,29)=1×17×23×29=11,339

(iii) 8, 9 and 25

Factor of 8=2×2×2×1

Factor of 9=3×3×1

Factor of 25=5×5×1

HCF (8,9,25)=1

LCM (8,9,25)=2×2×2×3×3×5×5=1,800