A class with p students has planned a picnic. Rs 50 per student is collected, out of which Rs 1800 is paid in advance for transport. How much money is left with them to spend on other items?

number of students = p


amount collected per student = 50 Rs


total amount collected = amount collected per student × amount collected per student


total amount collected = 50 × p = 50p


amount paid for transport = 1800 Rs


to find the money left we must subtract the amount paid from total amount collected


money left = total amount collected - amount paid for transport


Therefore, money left with them to spend on other items = 50p – 1800


90