Hey y'all. I need some help with my math problem:
In an assortment of cereals, 23 types contain oats and 25 types contain rice. Some of these cereals contain both oats and rice. If 16 cereals in this assortment contain oats but not rice, how many cereals contain rice but not oats?
Help please, I was like, "WTF?" when I saw this. Help! That's the question, I have to fill in the blank for the answer -_-
In an assortment of cereals, 23 types contain oats and 25 types contain rice. Some of these cereals contain both oats and rice. If 16 cereals in this assortment contain oats but not rice, how many cereals contain rice but not oats?
Help please, I was like, "WTF?" when I saw this. Help! That's the question, I have to fill in the blank for the answer -_-
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Well you know that 23 contain oats.
If 16 contain oats but no rice then 7 contain oats AND rice since 23-16=7
If 7 contain oats AND rice then of the 25 that contain any rice at all, 18 must only contain rice since 25-7=18. So the answer is 18.
If 16 contain oats but no rice then 7 contain oats AND rice since 23-16=7
If 7 contain oats AND rice then of the 25 that contain any rice at all, 18 must only contain rice since 25-7=18. So the answer is 18.
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This is a good problem to solve using Venn Diagrams.
Draw two intersecting circles. Label one "RICE" and the other"OATS"
Put the number 16 inside the oats circle, but NOT in the part tat is shared with the rice circle.
Now, know that the oats circle needs to have a total of 23 in it. We have 16 there already and therefore need to have 7 more. Put the number 7 in the overlapping portion of the two circles.
We need a total of 25 in the rice circle. We just put 7 in it. So, put (25 - 7) or 18 in the other part of the rice circle.
Read the answer in the diagram. There are 18 cereals with rice, but no oats.
Draw two intersecting circles. Label one "RICE" and the other"OATS"
Put the number 16 inside the oats circle, but NOT in the part tat is shared with the rice circle.
Now, know that the oats circle needs to have a total of 23 in it. We have 16 there already and therefore need to have 7 more. Put the number 7 in the overlapping portion of the two circles.
We need a total of 25 in the rice circle. We just put 7 in it. So, put (25 - 7) or 18 in the other part of the rice circle.
Read the answer in the diagram. There are 18 cereals with rice, but no oats.
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If 16 of the 23 cereals that contain oats contain ONLY oats, then the other 7 must contain both oats and rice, yes?
Since you know that just 7 cereals contain oats and rice, all of which are represented in both lists, you just need to take that 7 out of the 25 types containing rice to find the ones that contain ONLY rice. It's 18!
Since you know that just 7 cereals contain oats and rice, all of which are represented in both lists, you just need to take that 7 out of the 25 types containing rice to find the ones that contain ONLY rice. It's 18!