A box contains some purple, grey and brown chocolate bars. The ratio of the number of purple chocolate bars to the number of grey chocolate bars is 7 : 9. The ratio of the number of grey chocolate bars to the number of brown chocolate bars is also 7 : 9. What is the ratio of the number of purple chocolate bars to the number of brown chocolate bars in the box?
Purple |
Grey |
Brown |
7x7 |
9x7 |
|
|
7x9 |
9x9 |
49 u |
63 u |
81 u |
The number of grey chocolate bars is the repeated identity.
LCM of 7 and 9 = 63
Purple chocolate bars : Brown chocolate bars
49 : 81
Answer(s): 49 : 81