A survey of 500 college students indicated that 320 drank alcohol, 150 smoked, and 70 neither drank nor smoked.
The number of students who both drank and smoked was?
2007-05-07 15:07:14 · 10 answers · asked by granolagirl12001 2 in Science & Mathematics ➔ Mathematics
70 students did neither one so we're going to deal with only the 430 kids that either drank or smoked.
150 smoked and 320 drank and so the total that did one or the other is 470. since there are only 430 students some of the students had been counted twice. those are the students did both. to find how many of them there are, you subtract 470-430 so there are 40 students that drank and smoked.
2007-05-07 15:18:00 · answer #1 · answered by Anonymous · 0⤊ 0⤋
This is easy to solve if we draw a venn-diagram.
We can exclude the 70 that aren't really involved, bringing our population down to 500-70 = 430.
The people who both drank and smoked are included in boh the alcohol and smoked count. So adding alcohol and smoked (320+150 = 470) we get the total number who are "involved" with an extra count of the people in both categories. Thus, subtracting the number of people involved, 430 from 470 should give the number of students who both drank and smoked.
So: (320+150)-(500-70) = 40
2007-05-07 15:21:02 · answer #2 · answered by NSurveyor 4 · 0⤊ 0⤋
Let "d" be the number of students who drink but don't smoke, "s" be the number who smoke but don't drink, and let "b" be the number that do both. Then:
d + b = 320 (the total number that drink)
s + b = 150 (the total that smoke)
s + b + d + 70 = 500 (the total number of students)
You've got three equations with three unknowns. Find the value of b. Subtract the second equation from the third to get d + 70 = 500 - 150, so d = 280. Now use this in the first equation to find b: 280+b = 320, b = 40.
2007-05-07 15:13:00 · answer #3 · answered by Anonymous · 1⤊ 0⤋
40
If 70 did neither you're working with 500-70=430.
If 320 drank and 150 smoked (320+150=470) you can assume the difference did both. 470-430=40.
2007-05-07 15:30:12 · answer #4 · answered by Andrea 2 · 0⤊ 0⤋
Well, assuming that the difference between those numbers added up and the 500 original students in the question, then you end up with 40 who both smoke and drink.
2007-05-07 15:15:08 · answer #5 · answered by TC 2 · 0⤊ 0⤋
500 - 70 = 430
320 + 150 = 470
470 - 430 = 40 who both drank and smoked.
HTH
Doug
2007-05-07 15:15:28 · answer #6 · answered by doug_donaghue 7 · 0⤊ 0⤋
20
2007-05-07 15:13:54 · answer #7 · answered by kevkev93087 1 · 0⤊ 0⤋
Neither relatively. I don't have anything towards consuming, simply best do it as soon as each and every few years. Smoking I do have whatever towards. Watch a smoker die after being eliminated from a ventilator. It's a terrible factor.
2016-09-05 11:49:04 · answer #8 · answered by ? 4 · 0⤊ 0⤋
I've been drinking and smoking since I was Born
2007-05-07 15:16:00 · answer #9 · answered by Anonymous · 0⤊ 1⤋
a lot of people smoke and drink
2007-05-07 15:14:35 · answer #10 · answered by Anonymous · 0⤊ 1⤋