Answer:
3,090 diamonds
Step-by-step explanation:
To get 10 shards, you need to spend 30 diamonds.
First thing we need to find, how many rounds you need to play to get 1,024 shards if in each round you win 10 shards?
1,024/10 = 102,4
But you can not play 102.4 rounds, you only can play whole numbers, so we need to round it to the next whole number (not the previous one, because in that case, we would get less than 1,024 shards)
Then you need to play 103 rounds.
And each round costs 30 diamonds, then the total number of diamonds that you need is:
103*30 diamonds = 3,090 diamonds