The ratio should be written as:
mining:manufacturing:communication
Since there are three varieties of ratio's, then there is a specific answer for each. For the first example, the ratio is written as:
33/77:22/77:22/77
To find the integer ratio, divide all numbers with the smallest value, 22/77. The ratio becomes: 1.5:1:1
For the second example,
55/77:11/77:11/77
To find the integer ratio, divide all numbers with the smallest value, 11/77. The ratio becomes: 5:1:1
For the third example,
0:11/77:66/77
For this, exclude the ratio for mining because if you use this as the value, then all the numbers would be zero. Instead, divide using 11/77. The ratio becomes: 6:1.