A worker was hired for 7 days. Each day, he was paid Tk. 10 more than what he was paid for the previous day of work. The total amount he was paid in the first 4 days of work equaled the total amount he was paid in the last 3 days. What was his starting pay?

Correct Answer: Tk.90
Let, the first day wage is x Tk.ATQ, x + x + 10 + x + 20 + x + 30 = x + 40 + x + 50 + x + 60           x = 90