Find the value of given expression.

3 – (– 6) {– 2 – 9 – 3} ÷ 7{1 + (– 2) (– 1)}

The average weight of 15 oarsmen in a boat is increased by 1.6 kg when one of the crews, whose weighs 42 kg is replaced by a new man. Find the weight of the new man (in kg). 

If the amount received at the end of 2nd and 3rd year as Compound Interest on a certain Principal is Rs 24200, and Rs 26620 respectively, what is the rate (in %) of interest? 

To do a certain work, the ratio of the efficiencies of X and Y is 5:4. Working together, they can complete the same work in 10 days. Y alone starts the work and leaves after 5 days. The remaining work will be completed by X alone in:

The simple interest on a certain sum of money at the rate of 5 % per annum for 8 years is ₹ 840. Rate of interest for which the same amount of interest can be received on the same sum after 5 years is? 

How many numbers are there from 500 to 650 (including both) which are neither divisible by 3 nor by 7?

From an observation tower ‘h’ meter above the level of river, the angle of depression of a point on the near shore is A^° and that of a point directly on the far shore is B^°. Find the width of the river.

In an examination, 40% of the candidates write their answers in Urdu and the rest in Marathi. The average marks of the candidates writing in Urdu is 74 and the average marks of the candidates writing in Marathi is 77. What are the average marks of all the candidates?