Question
Three years ago, the ratio of ages of C and D was 3:4.
Seven years from now, the ratio of their ages will be 5:6. What is the current age of C?Solution
Let the age of C and D three years ago be 3x years and 4x years, respectively. So, present age of C = (3x + 3) years Present age of D = (4x + 3) years So, (3x + 3 + 7)/(4x + 3 + 7) = 5/6 6(3x + 10) = 5(4x + 10) 18x + 60 = 20x + 50 2x = 10 x = 5 So, the present age of C = 3x + 3 = 15 + 3 = 18 years
The hair of shaving brush clings together when removed from water due to –
Smog is a combination of –
Who defined the law of gravitation?Â
Iron, Nickel and Cobalt are the examples of
Who discovered the electron?
Which medium cannot propagate sound waves?
Which Nobel Gas is also known as ‘Stranger Gas’?
In the isothermal Process ______________ remains Constant.
Speed of sound in air is unaffected by change in :
Which of the following is the least penetrating power rays ?