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?

Question: 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?

Solution:
ধরি,
১ম দিন ছিলো x টাকা

২য় দিন = x + 10
৩য় দিন = (x + 20)
৪র্থ দিন = (x + 30)
৫ম দিন = (x + 40)
৬ষ্ঠ দিন = (x + 50)
৭ম দিন = (x + 60) টাকা

প্রশ্নমতে,
x + (x + 10) + (x + 20) + (x + 30) = (x + 40) + (x + 50) + (x + 60)
⇒ 4x + 60 = 3x + 150
⇒ 4x - 3x = 150 - 60
∴ x = 90