The Total solution for NCERT class 6-12
What will Rs 500 amounts to in 10 years after its deposit in a bank whichpays annual interest rate of 10% compounded annually?
Answer - 31 : -
Given,
The amount depositedin the bank is Rs 500.
At the end of firstyear, amount = Rs 500(1 + 1/10) = Rs 500 (1.1)
At the end of 2nd year,amount = Rs 500 (1.1) (1.1)
At the end of 3rd year,amount = Rs 500 (1.1) (1.1) (1.1) and so on….
Therefore,
The amount at the endof 10 years = Rs 500 (1.1) (1.1) … (10 times)
= Rs 500(1.1)10
If A.M. and G.M. of roots of a quadratic equation are 8 and 5, respectively,then obtain the quadratic equation.
Answer - 32 : -
Let’s consider theroots of the quadratic equation to be a and b.
Then, we have
We know that,
A quadratic equationcan be formed as,
x2 – x (Sum of roots) + (Product of roots) = 0
x2 – x (a + b) + (ab)= 0
x2 – 16x + 25 = 0 [Using (1) and (2)]
Therefore, therequired quadratic equation is x2 – 16x +25 = 0