Answer :

Ryan2
a) sum 3 + 7 =10
b) divide  £300 ÷ 10 =  £30
c) multiply:
     3 x 30 =  £90
     7 x 30 =  £210

Values are:  £90 and  £210
First you add the ratio  together 3+7=10 Then you do £300 divided by 10 = £30 
Then you do £30 X 3 (from the ratio in the beginning) which equals £90 
Then you do £30 X 7 (also from the ratio in the beginning) which equals £210 
The ratio is £90:£210 
Also you can add the ratios up so that it equals £300 the number you started with 
£90+£210=£300 
Hope I helped :)