Question
Three colleagues, M, N, and O, have an average age of
27. Ten years ago, their ages were in the ratio of 4:6:7. What is the average age of M and N today?Solution
Sum of their present ages = 3 × 27 = 81 Sum of their ages before 10 years = 81-30 = 51 Let their ages 10 years ago were 4x, 6x and 7x Then, 4x+6x+7x = 51 17x = 51 x = 3 their ages 10 years ago were 12, 18, 21 present age of M = 12+10 = 22 present age of N = 18+10 = 28 average of present age of M and N = (28+22)/2 = 25
The average of 20 numbers is 50. If two numbers, 40 and 60, are removed, what is the new average?
The area of a square garden is 400 m². Calculate the perimeter of the garden.
Quantity I: X: Aman, Bhuvan, and Chintu started a business with initial investments of Rs. (4a + 544), Rs. (2a + 896), and Rs. (...
The height of a right circular cone is 7 cm, and its volume is 733(1/3) cm³. Determine the diameter of the cone.
Arjun, Bheem, and Chetan start a business with initial investments of Rs. (p+1500), Rs. 'p', and Rs. (p-1000) respectively.
Quantity I: If the t...
A man travels 60 km at a speed of 30 km/h and then travels 90 km at a speed of 60 km/h. What is his average speed for the entire journey?
A merchant mixes two varieties of rice, one costing ₹55 per kg and the other costing ₹80 per kg, and sells the mixture at ₹75 per kg, making a pro...
If Seema had run at a speed of 14 km/hr instead of 7 km/hr, she would have covered 20 km more distance. What would have been the actual distance cover...
The equation of a hyperbola whose conjugate axis equals its transverse axis is:
A bag contains red, blue, and green balls in the ratio of 2:4:5. If two balls are randomly selected from the bag, the probability that both are blue is ...