Question
A man wants to invest Rs 20,220 in bank account of his
two sons whose age were 12 years and 16 years in such a way that they will get equal amount at age of 120 years @ 33(1/3)% per annum compounded annually. Find the share of younger son?Solution
For younger son Let the principal be x Time = 120 – 12 = 108 years Rate = 100/3 % For elder son Let the principal be Rs (20220 – x) Time = 120 – 16 = 104 years Rate = 100/3 % Amount of younger = Amount of elder x (1 + r/100)108 = (20220 – x) (1 + r/100)104 x (1 + 100/300)108 = (20220 – x) (1 + 100/300)104 [x/(20220 – x)] = (4/3)104/(4/3)108 [x/(20220 – x)] = 1/(4/3)4 [x/(20220 – x)] = 81/256 337x = 1637820 x = 4860 Alternate method: y/x =(4/3)(difference) =(4/3)4 = 256/81 81/337 × 20,220 = 4860
12 of 8 - 9 ÷ 3 × 16 - 17 + 6 of 4 - 15
f(x)=x+ ∣ x ∣ , then the function is:
P can complete a work in 25 days, while Q can complete the same work in 30 days. They work together for 5 days, and then P is replaced by R, who can com...
A particular sum of money, when invested at a simple interest rate, yields Rs. 3,000 as interest after 2 years. The same sum, whe...
A cone has a height of 12 cm and a base radius of 5 cm. A sphere with the same volume as the cone is constructed. What is the radius of the sphere?
Pipe ‘X’ can fill a tank in 20 hours while pipe ‘Y’ can empty it in 24 hours. They were operated alternately starting with pipe ‘X’. Find th...
A shopkeeper sold an article for Rs. 500 after offering a discount of 20%. If he earned a profit of 25%, then find the ratio of cost price to the marked...
If log₂(x) + log₄(x) + log₈(x) = 11, with x > 0, then the value of x is:
20, 247, 447, 620, ?, 885
315 people went to a park. The number of men is 25 more than the number of women and the number of adults is 15 more than the number of children. How ma...
Relevant for Exams:
