Question
A car covers a distance of 450 km at a constant speed.
If the car’s speed had been 15 km/h faster, it would have taken 1 hour less to cover the same distance. What is the original speed of the car?Solution
Let the original speed of the car be x km/h. Time taken = 450/x. With the new speed (x + 15), time taken = 450/(x + 15). According to the question: 450/x − 450/(x + 15) = 1. Solving this: 450(x + 15 − x) = x(x + 15). 450 × 15 = x² + 15x. x² + 15x − 6750 = 0. Solving for x, we get x = 75 km/h. Thus, the original speed is 75 km/h Ans. d
A man wants to invest Rs. 60660 in bank accounts of his two sons whose ages are 12 years and 16 years in such a way that they will get equal amount at a...
Find the mode of the following data:
6,15,18,6,18,11,23,22,6,18,15,22,12
The first odd number is 1, second is 3, third is 5 and fourth is 7 and so on, then find the 188th odd number?
The interest earned when a sum is invested at simple interest of 20% p.a., for 3 years, is Rs. 3000. What will be the total amount received after 2 year...
What is the median of the following list of numbers: 5, 3, 6, 9, 11, 19,12,20, and 1?
The current age of Anupama is 25% greater than Chinky's age. Four years ago, the ages of Beena and Chinky were in the ratio of 4:...
The average of 20 numbers is calculated as 35. However, it was later discovered that one of the numbers was mistakenly recorded as 28 instead of 82. Wha...
How many three digit numbers are divisible by 5?
If 8 times the eighth term of an Arithmetic Progression (AP) is equal to 12 times its twelfth term, then the 20th term of the AP will be
A shopkeeper sells a product for ₹720 at a profit of 20%. What was the cost price of the product?
