Pihu has to do a multiplication. Instead of taking 32 as one of the multipliers, he took 23. As a result the product went down by 72. What is the sum of the digits of the new product?
a) 15
b) 14
c) 13
d) 12
Sol:
Number = y
Decrease in number = 32y – 23y
= 9y
9y = 72
y = 8
