Mariam and Sana are excited that a new store just opened in town! They go together the first day it opens! Each time Mariam goes to the store she plans to spend Rs. 30, and each time Sana goes to the store she plans to spend Rs. 50. A few weeks from now, Mariam and Sana are surprised to find out that they have spent the exact same total amount of money at the store. What is the least possible number of times that Mariam has been to the store? Just write the number.

Since Mariam and Sana are excited that a new store just opened in town, and they go together the first day it opens, and each time Mariam goes to the store she plans to spend Rs. 30, and each time Sana goes to the store she plans to spend Rs. 50, and a few weeks from now, Mariam and Sana are surprised to find out that they have spent the exact same total amount of money at the store, to determine what is the least possible number of times that Mariam has been to the store the following mathematical reasoning has to be done:

To know how many times Mariam went and how many times Sana went to the store, since she spends Rs. 30 and the other Rs. 50, and they have spent the same after a few weeks, it is through the search for the lower common multiple of both numbers.

Thus, the common multiple less than 30 and 50 is 150 (30 x 5 or 50 x 3). Therefore, Mariam went to the store 5 times, while Sana went 3 times.