sarker33 wrote:
A watch is sold at a profit of 20%. If both the cost and selling price of the watch decreased by 100, the profit would be 5% more. Original cost price if the watch is ?
A. 450 B. 500 C. 550 D. 600
I am not sure, but the question seems a little awkward to me. Here is how I solved it:
20% profit means: (P-C)/C=0.2. Hence, P=1.2C.
If both P and C decreases 100, assuming that the new profit will be 25%, we have:
(P-100-(C-100))/(C-100)=0.25 which is equivalent to: (P-C)/(C-100)=0.25.
Substitute P with 1.2C, then: 0.2C=0.25*(C-100). Solve for C: C=500.
Answer is B