Question
Find the sum of all the possible values of 'a' such that
'9a5784' is always divisible by 3.Solution
A number is divisible by 3 when sum of its digits is divisible by 3.Sum of digits = 9 + a + 5 + 7 + 8 + 4 = a + 33(a + 33) is divisible by 3 when 'a' = 0, 3, 6 or 9Therefore, required sum = 0 + 3 + 6 + 9 = 18
An object moves towards a convex lens of focal length 20 cm with a velocity of 5 cm/s. When the object is at 30 cm from the lens, find the rate at which...
Two long parallel wires 2 cm apart carry 5 A and 3 A currents in the same direction. What is the force per unit length on one wire?
Which phenomenon does a hologram use to create an image?
Which of the following is not a characteristic of simple harmonic motion (SHM)?
A lens forms an image of magnification -2. If the object is placed 15 cm from the lens, what is the image distance?
A train runs along an unbanked circular track of radius of 10 m at speed of 36 km/h. The mass of the train is 16 kg.
What is the an...
The distance between the focus and the centre of curvature of a spherical mirror in terms of the radius of curvature R, is equal to:
What is colour of light related to?
Why does a large fire in the open appear to be fanned by strong winds?
Which of the following is an example of longitudinal waves in a gas medium?
Relevant for Exams:
