Three pipes A, B can fill the tank in 12, 20 hrs respectively and C can empty the tank in 30 hours. If the pipes are opened alternatively for 1 hour starting with A and drain pipe is kept open all the time. How much time will it take to fill the tank.

A factory buys 7 machines. 2 Machine A, 2 Machine B and rest Machine C. Prices of the machines are Rs 95000, Rs 75000 and Rs 43000 respectively. Calculate the average cost of these machines?

If the duty on an article is reduced by 40% of its present rate by how much per cent must its consumption increase in order that the revenue remains unaltered?

If x = 2 - 2^1/3 + 2^2/3, then the value of x³– 6x² + 18x + 18 is

The following table shows the numbers of chairs made of plastic and of steel in 5 different colours that were sold from a furniture showroom during a sale.

The total number of chairs of colour C3 sold are what percentage of all the chairs of these 5 colours sold, both plastic and steel ones put together? [Give your answer correct to 2 decimal places.]

What is the average of the first 13 odd numbers?

Chords AB and CD of a circle intersect externally at P. If CD = 11.6 cm, PD = 6.4 cm and PB = 7.2 cm, then AB (in cm) is equal to:

A sold a mobile phone to B at a gain of 25% and B sold it to C at a loss of 10%. If C paid ₹5,625 for it, how much did A pay (in ₹) for the phone?