A spinner has 12 sections of equal area. The probability of spinning red is 1/3 and the probability of spinning red or yellow is 3/4. How many yellow sections are there?
2007-01-26 16:15:32 · 5 answers · asked by Felicia F 1 in Science & Mathematics ➔ Mathematics
5.
The probability of spinning red or yellow is 3/4.
3/4 * 12 = 9 (sections of red and yellow)
The probability of spinning red is 1/3.
1/3 * 12 = 4 (red sections only)
(sections of red and yellow) - (red sections only) = 9 - 4 = 5 (yellow sections only)
2007-01-26 16:21:55 · answer #1 · answered by q_midori 4 · 1⤊ 0⤋
If the probability of spinning either red or yellow is 3/4, then 3/4 of the 12 sections, or 9, are either red or yellow. By similar reasoning, 1/3 of the 12, or 4, are red. Therefore, 5 of them are yellow.
2007-01-27 00:22:31 · answer #2 · answered by Chris S 5 · 1⤊ 0⤋
There are 5 yellow sections.
The ratio of yellow sections to total is
3/4 - 1/3 = 9/12 - 4/12 = 5/12.
Since there are 12 sections overall 12(5/12) = 5.
2007-01-27 02:17:45 · answer #3 · answered by Northstar 7 · 0⤊ 0⤋
given:
r is red sections
y is yellow sections
1/3*12=r
3/4*12=r+y
1/3*12=4=r
3/4*12=4+y
3/4*12=4+y
9=4+y
5=y
there are 5 yellow sections, 4 red sections, and 3 polka-dot sections.
2007-01-27 00:24:19 · answer #4 · answered by Will 1 · 0⤊ 0⤋
id say 5
2007-01-27 00:19:28 · answer #5 · answered by ~Zaiyonna's Mommy~ 3 · 0⤊ 2⤋