For a linear triangular element with (xi, yi) as the coordinates of the i^th node of the element the area=10units, the value of ∑αi from the standard relation αi+βiX+γiY=(2/3)*Area where X=∑xi, Y=∑yi is ___

(a) 10

(b) 20

(c) 30

(d) 40

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My query is from Boundary Value Problems topic in division Single Variable Problems of Finite Element Method