Question
A certain number of students can complete the assignment
together in 12 days. All of them started the assignment together, but 20 students left the assignment every day, so the assignment was completed in 16 days instead. Find the time it would take for 120 students to complete the same assignment.Solution
ATQ, Let the number of students be 'S' and efficiency of each student be 'e' units/day. Total assignment = S × 12 × e = '12Se' units ATQ, 12Se = S × e + (S - 20 × 1) × e + (S - 20 × 2) × e + (S - 20 × 3) × e + .... + (S - 20 × 15) × e Or, 12S = 16S - 20 × (1 + 2 + 3 + .... + 15) Or, 4S = 20 × 15 × (16/2) [since, sum of first 'n' natural numbers = (n/2) × (n + 1) ] So, 'S' = 600 Let the required time taken by 120 students be 't' days. So, 12 × 600 × e = 120 × t × e Or, 't' = (7,200/120) = 60
Rice crop is transplanted at spacing of 20 cm ×10cm by using 2 seedlings per hill. Calculate the plant population in 2000m2 area.
To create informative content and engagement material, along with simple messaging asking citizens to be aware, be cognizant and be receptive to SNF (s...
Association of fungi with roots of higher plants is known as:
The plants that are capable of growing in shade are termed as
Highest Ca is present in which manure?
In tea, which one of the following insecticides does not cause resurgence of pink mite.
What should be the spacing for standard variety of apple tree?
Â
Which two states account for almost 50% of the total agritech start-ups opened in the past 5 years?
Based on mode of action, activated clay exerts what type of effect?
Roughages contain > ___% Crude fibre and < _____% TDN.Â
