List of top Mathematics Questions on Commercial Maths

I went to a shop to purchase some refills costing Rs. 1.60 each but the clerk did not have change for my 20rupee note. I was constrained to purchase some 30 paise labels as well so that no money needed to be returned. After purchasing the maximum number of refills under the given constraints, how many labels did I have to purchase?
A company received two shipments of ball bearings. In the first shipment, 1 per cent of the ball bearings were defective. In the second shipment, which was twice as large as the first, 4.5 percent of the ball bearings were defective. If the company received a total of 100 defective ball bearings, then how many ball bearings were there in the first shipment?
A bag contains Rs. 216 in the form of one rupee, 50 paise and 25 paise coins in the ratio of 2:3: 4. The number of 50 paise coins is
Rohit, Harsha and Sanjeev are three typists who, working simultaneously, can type 216 pages in four hours. In one hour, Sanjeev can type as many pages more than Harsha as Harsha can type more than Rohit. During a period of five hours, Sanjeev can type as many pages as Rohit can during seven hours How many pages does each of them type per hour?
'A' wants to secure an annual income of Rs. 1500 by investing in 15\(\%\) debentures of face value Rs. 100 each and available for Rs. 104 each. If the brokerage is 1\(\%\), then the sum of money he should invest is
A person pays Rs. 975 in monthly instalments, each monthly instalment being less than the former by Rs. 5. The amount of the first instalment is Rs. 100. In what time, will the entire amount be paid?
A bought 4 bottles of beer and B bought one bottle of lager, lager per bottle costing twice that of the beer. C bought nothing but paid Rs. 50 for his share of the drink which they mixed together and shared equally. If C's Rs. 50 covered his share, then what is the cost of the lager?
In a house, there are six 40-watt lamps which are on for 5 hours a day and three 80-watt fans which are on for 10 hours a day. If electricity costs Rs. 2 per kilowatt hour, what is the monthly electricity bill?