Number of fruit baskets purchased by Mrs. William is 5
Solution:
Given that 
Annual membership fee of store where Mrs. William shops = $30 
Cost of one fruit basket which Mrs. William as gifts for her co-workers = $15 
Total amount spent by Mrs. William = $150 
Given that "b" represents number of basket purchased
Equation which models the above scenario is as follows 
15b+ 30=105 ------ (1) 
Where b represents number of fruit basket purchased by Mrs. William 
Need to calculate number of fruit basket purchased by Mrs. William 
For which we need to solve equation (1) for b 
On solving we get 
15b+ 30 = 105 
On Subtracting 30 from both sides we get 
15b + 30 – 30 = 105 – 30 
=> 15b = 75 
On dividing both sides by 15 we get 

As variable "b" represents number of basket purchased, hence we can conclude that number of fruit baskets purchased by Mrs. William is 5