A and B can do a piece of work in 40 days while B and C can do it in 60 days. If A is twice as good a workman as C, then C alone will do the work in

Meena, Neena and Raveena can knit a shawl in 6, 4 and 8 hours respectively. What portion of the shawl will they knit in 1 hour if they work together?

L.C.M is the smallest common multiple of the given numbers.

Tap A can fill a tank in 8 hours and tap B can empty the tank in 12 hours. How long would it take to fill the empty tank if both of them are opened together?

For such questions, we should see if the taps are filling or emptying the tank. We should also be careful about subtraction or addition of fractions. We should make the denominator equal or take L.C.M before subtracting or adding.

Latha, Chetan and Amar started a business. Latha invests Rs 5000 for 2 years, Chetan invests Rs.1000 for 15 months and Amar invests Rs 3000 for 10 months. If there is a profit of Rs. 1925, find out the share of Latha

The population of a town was 1,60,000 two years ago. If it has increased by 3% and 5% respectively in the last two years, find its present population

For such questions, we should be careful while finding the percentage increase in the population. We have to add the increased in number of population to the original population to get new population. We have to careful about order of increase in population.

The difference between C.I and S.I for 2 years at 10% per annum is Rs 50. Find the sum

For such questions, we should know the formulas for simple and compound interest.

An electric wire of length ‘I’ and area of cross-section has a resistance R ohms. Another wire of the same material having same length and area of cross-section 4a has a resistance of

The resistance of a wire of uniform diameter d and length L is R. The resistance of another wire of the same material but diameter 2d and length 4L will be

Reena borrowed Rs 8000 from Neena for 2 years at per annum compound interest. What C.I. did Veena pay to Neena?

Compound interest is the internet based on the principal amount and also the interest added to the sum. It's interst on that total amount.

A 500 gm packet of tea is sold for Rs 80 and a tooth brush costing Rs 11 is given free with it. The shopkeeper thus makes a profit of 15% on it. What did the shopkeeper pay for it?

In such questions, we should be careful about finding the actual selling price before finding the cost price. We should know the formula to find the profit.

The place with which a 7-digit number starts in Indo-Arabic System is

For such questions we should know the places of digits in Indo-Arabian system. The key part is counting the zeros.

0.6395 × 1000 =

When multiplying a decimal number by power of 10, we shift the decimal by point by the value of power of the number.

The place value of 5 in the number 215783 in Indo-Arabic System is

For such questions, we have to be careful to count from behind.

The remainder of 2¹⁰⁰ when divided by 7 is

For such questions, we should know the rules of indices.

If n = 10800 then find the total number of divisors of n and the number of even divisors

For such questions, we should know how to find prime factors.

For the combustion of n - octane
C8H18 + O2 → CO2 + H2O at 25°C (ignoring resonance in CO2)