Question
Two cars, A and B, are traveling in the same direction
on a highway. The ratio of their speeds is 3:4. If both cars increase their speeds by 15 km/h, the ratio of their speeds becomes 7:9. What is the original speed of the faster car (Car B)?Solution
Let the original speeds of Car A and Car B be 3x and 4x, respectively. After increasing speeds: Car A's new speed = 3x + 15 Car B's new speed = 4x + 15 New ratio = (3x + 15) : (4x + 15) = 7 : 9 Cross-multiplying: 9(3x + 15) = 7(4x + 15) 27x + 135 = 28x + 105 135 - 105 = 28x - 27x 30 = x Therefore, the original speed of Car B (the faster car) is 4x = 4 * 30 = 120 km/h Ans. a
A certain sum of money invested at R% p.a. fetches a compound interest (compounded annually) of 1560 and simple interest of Rs.1500 at the end of 2 year...
Atul has Rs.200 with him. He invested 40% of the amount at 5% p.a. for 6 years and rest at 20% p.a. for 5 years. Find the sum of simple interests receiv...
Rahul deposits a sum of money at an annual compound interest rate of 15%. After 1 year, the interest accumulated amounts to Rs. 180. If he increases his...
The difference between compound interest and simple interest at the same rate for Rs. 2400 for 2 years is Rs. 216. The rate of interest per annum is:
Mr. P invested Rs. ‘4x’ in scheme ‘A’ offering simple interest of 25% p.a. and reinvested the interest earned from scheme ‘A’ at the end of ...
'M' placed a specific amount of money into the 'SBI' Mutual Fund, which provides a 15% per annum simple interest rate. Simultaneously, 'M' invested the ...
Ravi lends Rs. 4800 to two of his friends. He gives Rs.2400 to the first at 15% p.a. simple interest. Ravi wants to make a profit of 20% on the whole. T...
- Simple interest on a sum for 2 years is Rs. 300 and compound interest for same period is Rs. 315. Find the principal. (Rate of interest is same for both.)
A person invested ₹15,000 at a simple interest rate of 20% per annum. Had the amount been invested at a compound interest rate of 20% per annum, compo...
- Nisha placed Rs. 25,000 in plan 'P' and Rs. 40,000 in plan 'Q'. Plan 'P' earns 14% simple interest annually for 2 years, and plan 'Q' earns 9% per annum fo...
