Sunil Bhagwat

Highest Common Factor and Lowest Common Multiple HCF -  To find the HCF of given numbers, we make a list of the factors of the numbers and find the greatest of the common factors. This is called Factorization method. LCM -  To find the LCM of the given numbers, we write down the multiples of each of the given numbers and find the lowest of their common multiples . The LCM of two numbers cannot bigger than their product. Watch the video on YouTube : 

Railways Group D Question 1: In a hostel of 50 girls there are food provisions for 40 days. If 30 more girls join the hostel, the food provisions will last for: A) 35 days B) 30 days C) 25 days D) 20 days Answer: C) 25 days Explanation: 50 girls can eat for 40 days  1 girls can eat for 50 * 40 = 2000 days If 30 more girls join, so number of girls  = 50 + 30 = 80 Number of days the food will last = 2000 / 80 = 25 days Hence, option C is correct answer Question 2: The book "Indomitable Spirit" is written by: A) Jhumpa Lahiri B) Khushwant Singh C) Rajmohan Gandhi D) Dr. A. P. J. Abdul Kalam Answer: D) Dr. A. P. J. Abdul Kalam Question 3: A man bought article and sold it at a gain of 10%. If he had bought it at 20% less and sold it for Rs. 10 more, he would have made an profit of 40%. The cost price of the article is: A) 500 B) 480 C) 450 D) 400 Answer: A) 500 Explanation:  Let u