Mrs. Rifkin had 84 oranges. Twenty four of her oranges were rotten. The rest were either ripe or unripe. There were 18 more ripe oranges than unripe oranges. Find the ratio of the number of ripe oranges to the number of rotten oranges to the number of unripe oranges.
84 oranges - 24 rotten= 60 oranges left
39 are ripe and 21 are unripe ripe : rotten : unripe = 39:24:21 simplifies to 13:8:7
Let the number of unripe oranges = U
Let the number of ripe oranges = R
There were 18 more ripe oranges than unripe oranges. In other words,
the number of ripe oranges = the number of unripe oranges + 18
R = U + 18
The number of rotten oranges = 24
84 – 24 = 60
R + U = 60
Since R = U + 18 we can substitute U + 18 in for R:
R + U = 60
U + 18 + U = 60
U + U = 60 – 18
2U = 42
U = 21
Now that we know the value of U we can find the value of R
R = U + 18
R = 21 + 18
R = 39
the number of ripe oranges = 39
the number of rotten oranges = 24
the number of unripe oranges = 21
num of ripe oranges : num of rotten oranges : num of unripe oranges = 39 : 24 : 21 = 13 : 8 : 7