An assistant's monthly pay was raised by 10%, and a fixed conveyance allowance of ₹1,500 was then added on, taking his monthly amount to ₹34,500. What was his monthly pay before the rise?

Undo the steps in reverse order. Take off the flat ₹1,500 first: 34,500 - 1,500 = ₹33,000, which is the raised pay. Then undo the 10% rise by DIVIDING: 33,000/1.10 = ₹30,000. Check: $30,000\times 1.1=33,000$, plus 1,500 = 34,500. ₹31,364 divides ₹34,500 by 1.10 without removing the flat allowance first. ₹33,000 stops one step early and quotes the raised pay. ₹29,550 undoes the rise by taking 10% OFF ₹34,500 - subtracting a rate never undoes adding it.