If in the UK, open a cash ISA (tax free) and put it in that. Interest is little at the moment. So, if you can afford to tie up the cash long term, inquire about a fixed term ISA. Unlike the Stock Market, your money is safe in an ISA.
It will take 19 years.
In order to start with a good investment, one should invest anywhere from $500 to $2500. This way it will be a good lump sum to start earning the best interest rates possible.
2500
2500 is the answer
The future tense for invest is, will invest.
40 percent of 2500 = 100040% of 2500= 40% * 2500= 0.40 * 2500= 1000
56% of 2500 = 56% * 2500 = 0.56 * 2500 = 1,400
60% of 2500= 60% * 2500= 0.6 * 2500= 1500
75% of 2500= 75% * 2500= 0.75 * 2500= 1875
79% of 2500 = 79% * 2500 = 0.79 * 2500 = 1,975
20% off $2500= 20% discount applied to $2500= $2500 - (20% x $2500)= $2500 - $500= $2000
12.5 percent of 2500 = 312.512.5% of 2500= 0.125 * 2500= 312.5