2007-05-04 19:39:20 · 8 answers · asked by June t 1 in Science & Mathematics ➔ Mathematics
x= number of boys
y= number of boys
t= total number of pupils
x/3 + y/4 = 3/10(x+y)
x+y = t
After solving: x/t = 3/5
2007-05-04 19:58:10 · answer #1 · answered by terry n 4 · 0⤊ 0⤋
1/10
2007-05-04 20:51:50 · answer #2 · answered by giftedman88 3 · 0⤊ 2⤋
1/3 x 3/10( the 3's cancel out)=1/10 boys wear glasses
2007-05-04 19:52:22 · answer #3 · answered by Dave aka Spider Monkey 7 · 0⤊ 2⤋
Let
P(x) = probability wears glasses
P(x|b) = probability wears glasses given its a boy
P(x|g) = probability wears glasses given its a girl
P(b) = probability boy
P(g) = probability girl
Given
P(x) = 3/10
P(x|b) = 1/3
P(x|g) = 1/4
We know
P(b) + P(g) = 1
We have:
P(x) = P(x|b)P(b) + P(x|g)P(g) = 3/10
(1/3)P(b) + (1/4)[1 - P(b)] = 3/10
(1/12)P(b) + 1/4 = 3/10
(1/12)P(b) = 1/20
P(b) = 12/20 = 3/5
2007-05-04 21:03:36 · answer #4 · answered by Northstar 7 · 0⤊ 0⤋
Let b + (n - b) = n pupils
3n/10 wear glasses
b/3 wear glasses
(n - b)/4 wear glasses
b/3 + (n - b)/4 = 3n/10
40b + 30n - 30b = 36n
10b = 6n
b = 6n/10 = (3/5)n
2007-05-04 19:53:29 · answer #5 · answered by Helmut 7 · 1⤊ 0⤋
BOYS=1/3
TOTAL=3/10
FRACTION OF BOYS=1/3 MULTIPLY BY 3/10
=1/10
2007-05-04 19:45:47 · answer #6 · answered by Anonymous · 0⤊ 2⤋
25 percent of 33 percent would the difference which would be 8 percent then the boys would be that
2015-07-03 17:46:35 · answer #7 · answered by new_bumble_bee 7 · 0⤊ 0⤋
Let total number of pupils = X
Number who wear glasses = 3X/10
No. of boys who wear glasses = X / 10
No. of girls who wear glasses = 3X / 40
2007-05-04 19:57:03 · answer #8 · answered by Como 7 · 0⤊ 1⤋