Question 1185930
Here's how to break down this problem:

**a) Percentage Increase in John's Earnings**

1. **James' Initial Earnings:** James' earnings increased by 10% to 7200 kshs.  Let 'x' be his initial earnings.
   * x + 0.10x = 7200
   * 1.10x = 7200
   * x = 7200 / 1.10
   * x ≈ 6545.45 kshs

2. **John's Initial Earnings:** The ratio of James' to John's earnings was 4:3.
   * John's initial earnings = (3/4) * James' initial earnings
   * John's initial earnings = (3/4) * 6545.45
   * John's initial earnings ≈ 4909.09 kshs

3. **John's New Earnings:** The sum of their new earnings was 15600 kshs.
   * John's new earnings = Total new earnings - James' new earnings
   * John's new earnings = 15600 - 7200
   * John's new earnings = 8400 kshs

4. **Percentage Increase in John's Earnings:**
   * Percentage increase = [(New earnings - Initial earnings) / Initial earnings] * 100
   * Percentage increase = [(8400 - 4909.09) / 4909.09] * 100
   * Percentage increase ≈ 71.1%

**b) James' Share of Sales Money**

1. **Total Contributed:** James and John contributed their new earnings, totaling 15600 kshs.

2. **Bags of Maize Purchased:**
   * Bags purchased = Total contributed / Cost per bag
   * Bags purchased = 15600 / 1175
   * Bags purchased = 13.27 bags. Since you can't buy parts of bags, we'll use 13 bags.

3. **Total Revenue from Sales:**
   * Total revenue = Bags sold * Selling price per bag
   * Total revenue = 13 * 1762.50
   * Total revenue = 22912.50 kshs

4. **Total Profit:**
   * Profit = Total revenue - Total cost
   * Profit = 22912.50 - 15600
   * Profit = 7312.50 kshs

5. **James' Share:**  James' share is proportional to his contribution.
   * James' share = (James' new earnings / Total new earnings) * (Total Revenue)
   * James' share = (7200 / 15600) * 22912.50
   * James' share ≈ 10565.38 kshs

**Therefore:**

* **a)** John's earnings increased by approximately **71.1%**.
* **b)** James received approximately **10565.38 kshs** from the maize sales.