➥ Let the number of blue gems be x, green gems be 2x and red gems be x + 13.
According to question,
5x + 1 × 2x + 20(x + 13) = 2150
On solving equation, we get
27x + 260 = 2150
27x = 2150 - 260
27x = 1890
x = 1890/27 = 70 blue gems.
2 × 70 = 140 green gems.
70 + 13 = 83 red gems.
Hence, We have 70 blue gems, 140 green gems and 83 red gems.