In a ratio you must figure out the total number of parts. In this case we have a 4 part ratio and a 3 part ratio for 7 parts.
Each part of the ratio must be 1/7 of 56. So we divide 56/7 =8.
That means each part of the ratio is equal to 8.
We have 4 parts of the ratio that we must multiply by 8 4*8= 32
We have 3 parts of the ratio that we must multiply by 8 3*8 = 24
Therefore the ratio should be 32:24