1)i want to send 15$ to 10 BTC (total 150$) is there way to send them all in same time with same fee like i send 150$ to one address ?
2) if Number 1 possible how can do this using blockchain.info and how to detect fee ?
Do you mean 10 bitcoin addresses? Yes you can send them at the same time but if you are going to use blockchain.info the feature of it's multiple send has been removed. In signature campaign's the manager is sending the payments to the participants at the same time and that makes the fee cheaper. You can use bitcoin core or electrum for sending multiple addresses that $15. The thing in electrum, the fees are not the same with others it's quite higher for me.