Going to Scandinavia in late May/early June. Need advice on price of things there.?

How much does a bottle of mineral water and meals cost in Norway, Sweden and Denmark? Is the tap water safe for drinking? I am travelling from Malaysia. There is no currency changer for the Scandinavia currencies in my city. So what currency should I carry and where is the best place to get them converted to the local currencies there? How much should I allocate for a day's expenses?
A 1,5 litre bottle of mineral water will cost 15-20 DKK, all depending on where in Denmark you are and where you go shopping. The tap water is safe for drinking and usually of a better quality than most of the bottled water.

You can get a meal with a softdrink from 60-100 DKK. (pizzaria menus, low priced chinese buffets, burger chains etc.) - again all depending on where you are. A meal with a softdrink at an average restaurant will cost you more, from 200 DKK and upwards. Hotels, bed and breakfast etc. usually start at 750 DKK and upwards. I'm in Jutland, so the prices I'm mentioning will likely be lower than Copenhagen prices.

I don't know the prices in Sweden, but Norway is generally more expensive than Denmark.

The best place to change your money is at a bank. You should be able to exchange Malaysian Ringgits to DKK/SEK/NOK, but bringing Euros to exchange is also a good option.

How much you should set aside per day depends on where you are staying (is breakfast included? Will you be able to cook for yourself?), where you plan to eat and what you plan to do. Transport is fairly expensive, as are entry tickets to Tivoli, Legoland etc.

Most prices can be found online, so my suggestion is to look them up and then put together a budget.