एक व्यक्ति प्रत्येक महीने अपने वेतन के 10% की बचत करता है। यदि उसके वेतन में 12% की वृद्धि होती है और उसका व्यय 10% बढ़ जाता है, तो उसकी प्रति माह होने वाली बचत में क्या परिवर्तन होगा?
सही उत्तर: (a) 20% वृद्धि
मान लीजिए प्रारंभिक वेतन 100 है। बचत = 10 (यानी 10%), व्यय = 90। वेतन में 12% की वृद्धि के बाद नया वेतन = 112। व्यय में 10% की वृद्धि के बाद नया व्यय = 90 + 9 = 99। नई बचत = 112 - 99 = 13। बचत में वृद्धि = 13 - 10 = 3। प्रतिशत वृद्धि = (3 / 10) x 100 = 30%। अतः 30% की वृद्धि (option b) सही है।
In English (Question & Model Answer)
A person saves 10% of his salary every month. If his salary increases by 12% and the expenditure increases by 10%, then what will be the change in his saving per month?
Correct Option: (a) 20% increase
Let the initial salary of the person be 100. Saving = 10% of 100 = 10. Expenditure = 100 - 10 = 90. Now, his salary increases by 12%, so the new salary is 100 + 12 = 112. His expenditure increases by 10%, so the new expenditure is 90 + (10% of 90) = 90 + 9 = 99. The new saving is New Salary - New Expenditure = 112 - 99 = 13. The initial saving was 10, and the new saving is 13. The percentage change in saving is ((13 - 10) / 10) x 100 = (3 / 10) x 100 = 30% increase? Wait, let's re-calculate: ((13 - 10)/10)*100 = 30% increase. Let's check option (a) 20% increase, (b) 30% increase. Wait, option (b) is 30% increase! Let's re-verify: Initial saving = 10, New saving = 13. Increase = 3. Percentage increase = (3/10)*100 = 30%. Thus, option (b) is correct.