Question
The average wage of a group of 30 labourers is Rs. 400.
If 4 persons receiving average wage of Rs. 320 leave the group and 2 persons receiving average wage of Rs. K join the group, then the average wage of the group increases by Rs. 45. Find the value of ‘K’.Solution
Total wage of 30 labourers in the initial group = 30 × 400 = Rs. 12000 New average wage of the group = 400 + 45 = Rs. 445 New number of labourers in the group = 30 – 4 + 2 = 28 So, according to the question, 12000 – 4 × 320 + 2K = 445 × 28 Or, 12000 – 1280 + 2K = 12460 Or, 12000 + 2K = 12460 Or, 2K = 12460 – 12000 = 1740 Or, K = (1740/2) = 870
What is the average number of DELL laptops sold in all the given years?
A vendor buys a box of fruits for ₹720 and sells them at a 25% profit. If he sells 60% of the fruits, what will be his profit on this transaction?
If the ratio of the ages of A and B is 3:5, and after 5 years, the sum of their ages will be 50 years, what are their current ages?
If a hyperbola passes through the point (4, 0) and has foci at (±5, 0), and the length of its conjugate axis is 6, then the eccentricity is:
I). p 2  – 5p – 126 = 0
II). q 2  + 9q – 90 = 0
From a point located x meters away from the base of a tree, the angle of elevation to the top of the tree is 60 ∘ . If the tree is 54 mete...
If sec θ + tan θ = 5, then find the value of sin θ.
A 60-liter solution contains 30% alcohol. How much pure alcohol must be added to make the solution 50% alcohol?
A trader sells two articles for ₹450 each. He makes a profit of 20% on the first and a loss of 10% on the second. What is his overall profit or loss p...