I could do with some help figuring out how to explain these please...
Craig is arranging plates of food for a part. He has 3 types of sandwich, 2 types of cake and 4 types of biscuits/ Which shows the number of possible combinations of shadwich, cake and biscuit on a plate?
(3 x 2) + (3 x 4)
3 x 2 x 4 this is the correct answer
(3 x 4) + (2 x 4)
3 + 2 + 4
(2 x 3) + ( 2 x 4)
A milkman and a baker deliver to the same house. In a period of 28 days the milkman calls every second day and the baker every third day. They meet at the house twice in the first 7 days. How many more times do they meet during the 4 week period?
My daughter attempts this by drawing 2 horizontal time lines for each person and seeing where the matches lie, but is there a quicker/easier way?
Quick replies. No doubt others will work through completely for you.
Pick a sandwich, tuna say
. For each sandwich you can have 2 types of cake (x2). For that sandwich and and each of the two types of cake you can have 4 types of biscuit (x4). 3 different types of sandwich (x3)
all the others have + signs in anyway, so if confident can go straight to correct answer (a 5 second question)
Your DD is essentially correct. A lowest common multiple question. The lowest common multiple of 2 and 3 is 6. So once they meet, they will then meet every 6 days. Use rest of info to determine first meet point. They meet twice in the first week, therefore they must first have met on either the first or second day of the first week. Accordingly you can divide 6 into 28 to obtain answer. Without the additional info they could first have met on the 6th day, and which would lead to a different answer.