Final answer:
The question involves rounding £135.99 to two significant figures. The result is £140, as the first two significant digits are '1' and '3', and the succeeding digit '5' caused the second digit to be rounded up.
Step-by-step explanation:
The question asks how to round £135.99 to two significant figures. When rounding to significant figures, the first step is to identify the first non-zero digit, which, in this case, is '1' and represents the first significant figure.
Next, look at the digit to the right of the first significant figure, which is '3' and is the second significant figure in this context.
All the other digits after the second significant figure should be considered for rounding.
As '5' is the next digit after '3', we round the '3' up by one to '4'.
Therefore, £135.99 rounded to two significant figures is £140.