Question
Quantity 1 : A and B together can paint a wall in 12
hours. A alone can paint it in 18 hours. B paints for 5 hours, and then A completes the remaining work. How many total hours did they take to paint the wall? Quantity 2 : X and Y together can paint a wall in 14 hours. X alone can paint it in 20 hours. Y paints for 8 hours, and then X completes the remaining work. How many total hours did they take to paint the wall?Solution
For Quantity 1 : A’s rate = 1/18, B’s rate = 1/12 - 1/18 = 1/36 Work done by B in 5 hours = 5 × 1/36 = 5/36 Remaining work = 1 - 5/36 = 31/36 Time taken by A to finish remaining work = (31/36) ÷ (1/18) = 15.5 hours Total time = 5 + 15.5 = 20.5 hours Quantity 1 = 20.5 hours For Quantity 2 : X’s rate = 1/20, Y’s rate = 1/14 - 1/20 = 3/140 Work done by Y in 8 hours = 8 × 3/140 = 6/35 Remaining work = 1 - 6/35 = 29/35 Time taken by X to finish remaining work = (29/35) ÷ (1/20) = 16.57 hours Total time = 8 + 16.57 = 24.57 hours Quantity 2 = 25.71 hours Correct option : b) Quantity 1 < Quantity 2
What sum of money must be given at simple interest for 3 months at 4% per annum in order to earn Rs. 240 interest?
Atul invested in scheme A and B that provide simple interest at the rate of 12% and 15% for 3 years and 5 years, respectively. Interest received from sc...
- Rs. 3,300 is put into a savings scheme at a simple interest rate of 36% per annum for 3 years. The maturity amount is then invested in a business venture t...
If the difference between the simple interest and compound interest, compounded annually, received on a principal amount of Rs. 25000 at an interest rat...
A man invested Rs. 5,000 at simple interest of 'x%' p.a. and received Rs. 12,000 after 2 years. If he had invested Rs. 25,000 at simple interest of 'x%'...
 If the simple interest for 5 years is equal to 20% of the principal, then the interest will be equal to the principal after ________ years.
Karan invested Rs. (x + 250) in Scheme A at a simple interest rate of 25% p.a. for 2 years, and the interest received is Rs. 1000. He then invested Rs. ...
Raman gave 50% of his savings of 126150 to his wife and divided the remaining sum among his two sons Aman and Bhusan of 15 and 13 years of age respectiv...
Rs. 5000 when invested at simple interest of r% p.a. amounts to Rs. 6000 in 24 months. If the same sum had been invested for 1 year at compound interest...
'P' invested Rs. 2,00,000 at compound interest of ___% p.a., compounded once every 4 months. If he kept the amount invested for 12 months, then interest...
