Use & numbers and texts formulas.
="The average time taken on "&B13&" is "&TEXT(L18,"0.0")&" hours, with a cost of "&TEXT(L20,"£0,000") & ". With the longest session taking, " &TEXT(H13,"0.0") & " hours."
The average time taken on Model Simulations is 119.1 hours, with a cost of £9,999. With the longest session taking, 400.3 hours.
B13 = Model Simulations
L20 = £9,999
H13 = 400.3