1. The best thing to do is to find out what 1% is. 235/100= 2.35
As you're looking for 27%, you then multiply 2.35*27= 63.45
As you're increasing it, you've then got to add this to the original amount.
235+63.45= 298.45
2. Again, find 1%. 24/100= 0.24
0.24*9= 2.16
24+2.16= 26.16
3. Find 1%. 1120/100= 11.2
As you're looking for 13.5%, you then multiply this by 13.5
11.2*13.5= 151.20
As you're subtracting, you then take this away from the original number.
1120-151.20= 968.80
4. This time, you can find 10%.
0.057/10= 0.0057
0.0057*5.5= 0.03135.
You've then got to subtract this as you're decreasing the number.
0.057-0.03135= 0.02565.
Sally's investment is now worth £585. (Find the 30% and add it on) and Susie's investment is now worth £585 (Find the 10% and subtract). They both have the same amount of money.
Hope this helps :)