The present age of a brother is 2 years more than four times the age of his sister. Two years hence, brother’s age will be 4 years more than twice the age of the sister. Find the present age of the brother.
Let the sister’s present age be ‘n’ years.
=> brother’s present age = (4n + 2) years
So, according to the question
(4n + 2 + 2) = 2 (n + 2) + 4
=> 4n + 4 = 2n + 8
=> n = 2
Hence, brother’s present age = (4n + 2) = 10 years
for 1 hour he will do 1/y work...
for 2 hour he will do 2/y work...
So for 3 hours he will do 3/y work...
remaining work= 1-(3/y)
therefore answer is (y-3)/y.
The price of a product was reduced by 35% last year. During this year by what percentage should it be increased to bring it back to the original price of last year?
A tempo, while travelling at 70 kmph, uses 40% more petrol than it uses while travelling at 50 kmph for travelling a certain distance. Using one litre of petrol, it can travel 19.6 km at 50 kmph. How far can the tempo travel (in KMs) on 10 litres of petrol at a speed of 70 kmph?
At 50 kmph , one km distance uses 1/19.6 litre petrol.
At 70kmph, one km distance uses 1.4/19.6 litre petrol
Distance traveled with 10 ltrs @ 70kmph = 10*19.6/1.4= 140 kms.
Students attend our lectures, not because the mathematics we teach ‘makes lots of fun’ for us, but because they believe they can learn some essential knowledge from us. And each of our young students has only one life to live. We should therefore be a
H. Behnke
Mathematics is the handwriting on the human consciousness of the very Spirit of Life itself.