Two typewriters were sold for $8000 each. The first was sold at a profit of 40% and the second at a loss of 40%. What was the cost price of the first typewriter?
The Usual Method
Let the cost price of the first typewriter be ‘x’.
Hence, selling price = 1.4x (including 40% profit)
Estimated Time to arrive at the answer = 60 seconds since the division will take some time.
We know that selling price is 1.4 times the cost price. Hence, = the cost price.
We know that = 0.1428…
is a division by 7 (Since, 14 is a multiple of 7). Hence, the numbers after the decimal point will be of the type .14… The only option matching this criterion is option ‘5’.
Estimated Time to arrive at the answer = 10 seconds.