If 7% of the sale price of a watch is equivalent to 8% of its cost price and 9% of its sale price exceeds 10% of its cost price by Re 1, then what is the cost price of the watch?	Pick one:
A) Rs 400
B) Rs 350
C) Rs 300
D) Rs 280
E) Rs 380
Let C.P. = X and S.P. = Y   =&gt; 7 % of Y = 8% of X and 9% of Y =10% of X + 1   =&gt; 7Y = 8X and 9Y = 10X + 100   =&gt; 9 x (8X / 7) = 10 X + 100   =&gt; X = Rs. 350   ANSWER:Rs 350
<result>B</result>
If 7% of the sale price of a watch is equivalent to 8% of its cost price and 9% of its sale price exceeds 10% of its cost price by Re 1, then what is the cost price of the watch?