SOLUTION: 1.) A shop keeper sold 2 bicycles for #1,500 each. On onevhe gains 25% and on the other he loses 20%. His gain or loss percent in the whole transaction is?

Question 1081196: 1.) A shop keeper sold 2 bicycles for #1,500 each. On onevhe gains 25% and on the other he loses 20%. His gain or loss percent in the whole transaction is?
Answer by Theo(13342) (Show Source): You can put this solution on YOUR website!
he sells both bikes for 1500 each.
let x = the cost of the first bike.
let y = the cost of the second bike.
selling price for the first bike is 1.25 * x.
selling price for the second bike is .80 * y.
that's because x + .25 * x = 1.25 * x and because y - .20 * y = .80 * y.
1.25 * x = 1500
.80 * y = 1500
his total selling price for both bikes was 3000
1.25 * x + .80 * y = 3000
you have one equation in two unknowns.
you need to make this one equation in one unknown in order to be able to solve it.
since you kmow that both 1.25 * x and .8 * y are each equal to 1500, then you know that 1.25 * x must be equal to .8 * y
therefore, since .8 * y is equal to 1.25 * x, in the equation of 1.25 * x + .8 * y = 3000, you can replace .8 * y with 1.25 * x to get:
1.25 * x + 1.25 * x = 3000
combine like terms to get 2.5 * x = 3000
solve for x to get x = 3000 / 2.5 = 1200.
since 1.25 * x = .8 * y, and since x = 1200, you get:
1.25 * 1200 = .8 * y.
solve for y to get y = 1.25 * 1200 / .8 = 1875.
the first bike cost 1200
the second bike cost 1875.
the first bike cost 1200 and was sold for 1500 with a profit of 300 which is equal to 300 / 1200 = .25 * 100 = 25%.
the second bike cost 1875 and was sold for 1500 with a loss of 375 which is equal to 375 / 1875 = .2 * 100 = 20%.
solution looks good.

.
RELATED QUESTIONS
respected sir Q) a man sold two chairs for rs 500 each. on one he gained 20% and on the... (answered by JulietG,josmiceli)

A shopkeeper sold two articles for $ 48 each. He made a 25 % profit on one article and... (answered by josmiceli)

A man sold two Rs 1000 each.on one he gain 30% and the other he loss 20%.find the overall (answered by CubeyThePenguin,ikleyn,greenestamps)

a shop keeper sells two phones for rs 6000, one at a gain of 25 percent and the other at... (answered by Edwin McCravy)

By selling two tables for 1200/- each, a man gains 10% on one and losses 10% on another.... (answered by Theo)

Martha's millinery sold two evening gowns at the same price. Based on their cost, the... (answered by Boreal)

A trader sells two T-shirts at $48 each. She gains 25% on the cost price for one T-shirt... (answered by MathTherapy)

A salesman bought 2 dozen television sets at $300 each. He sold two-thirds of them at a... (answered by stanbon)

a shop keeper buys 30 limes for $4.50. five of the limes were rotten. so he couldn't sell (answered by josgarithmetic)