সঠিক উত্তর হচ্ছে: ২০
ব্যাখ্যা: Let\'s consider the salary of an officer to be 100.\nSo, If the salary is increased by 25%, then the new salary - 100+ [100×(25/100) ] = 100+25 = 125\nSo, his new salary is 125\nTo make his salary original 25 must be subtracted from 125, then his salary will be 125-25 = 100 or original salary.\nSo, To find the percentage of salary which must be decreased we must find that 25 is what percentage of 125.\nSo, decrease% = (25/125) × 100 = 1/5 × 100 = 20%\nAnswer) 20% of his new salary must be deducted so that his salary becomes Original.