According to the question,
Change in length of rectangle = - 50% = a
Change in breadth of rectangle = 100% = b
Net effect = a + b + (ab)/100 %

Correct Option: E

According to the question,
Change in length of rectangle = - 50% = a
Change in breadth of rectangle = 100% = b
Net effect = a + b + (ab)/100 %
= - 50 + 100 + [(-50) (100) / 100]%
= 0%

III     II       I   
100 150 120
Required percentage = (150/120) x 100%

Correct Option: A

III     II       I   
100 150 120
Required percentage = (150/120) x 100% = 125%

Let the maximum marks be N .
According to the question,
Then, 780 - 728 = 5% of N

Correct Option: A

Let the maximum marks be N .
According to the question,
Then, 780 - 728 = 5% of N
⇒ 52 = 5% of N
∴ N = 5200/5 = 1040

Total marks obtained = (76 + 48 + 84 + 38 + 72) = 318
Maximum marks = 5 x 100 = 500

Correct Option: C

Total marks obtained = (76 + 48 + 84 + 38 + 72) = 318
Maximum marks = 5 x 100 = 500
∴ Requirred percentage = (318/500) x 100 % = 63.6 %

Saving = 20%
Expenditure = 80% = ₹6000

Since 80% is 6000 so 20% would be 6000/4 = ₹1500

Correct Option: C

Saving = 20%
Expenditure = 80% = ₹6000

Since 80% is 6000 so 20% would be 6000/4 = ₹1500
Hence net saving per month = ₹1500