If tan (5x - 10°) = cot (5y + 20°), then the value of x + y is
Expression : tan (5x - 10°) = cot (5y + 20°)
=> $$tan(5x-10^\circ)=cot[90^\circ-(-5y+70^\circ)]$$
Using, $$cot(90^\circ-\theta)=tan\theta$$
=> $$tan(5x-10^\circ)=tan(-5y+70^\circ)$$
=> $$5x-10^\circ=-5y+70^\circ$$
=> $$5x+5y=70^\circ+10^\circ$$
=> $$5(x+y)=80^\circ$$
=> $$(x+y)=\frac{80^\circ}{5}=16^\circ$$
=> Ans - (B)
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