original number ---- 10x + y, where x is the tens digit and y is the unit digit
10x + y = 18 or y = 18-10x
reversed:
10y + x = 81
solving by substitution, ....10(18-10x) + x = 81
180 - 100x + x = 81
-99x = -99
x = 1
then y = 18-10 = 8
He sold 18 toys at RS 18 each
so each toy cost RS 1
then 81 would cost 81
A shopkeeper sold a certain number of toys.The number of toys as well as da price of each toy in Rs. was a two digit number. By mistake he reversed da digits of both the number of toys he sold and the price of each toy.As a result, he found that his stock account at the end of the day showed 81 items more than actual present price
2 answers
correct
1 answer