Question
The number of five–digit telephone numbers having
at least one of their digits repeated isSolution
The number of five–digit telephone numbers which can be formed using the digits of 0, 1, 2,...., 9 is 105. The number of five-digit telephone numbers which have none of their digits repeated is 10P5 = 10 × 9 × 8 × 7 × 6 = 30240 Hence the required number =105 - 30240 = 69760
Consider two concentric circles having radii 17 cm and 15 cm. What is the length (in cm) of the chord, of the bigger circle, which is a tangent to the s...
If O is the orthocentre of ΔABC , if ∠ BOC = 105 0 then what is the measure of ∠ BAC?
In the given figure CD is parallel to AB then ∠y is?
If O is circumcentre of acute angled triangle ABC, if ∠ OBC = 150 then ∠BAC = ?
- Length of a chord in a circle of radius 'r' cm, is 40 cm and distance between chord and centre of the circle is 21 cm. Find the value of (2r + 1).
The sides of a triangle are 10 cm, 17 cm, and 21 cm. Find the area of the triangle using Heron’s formula.
The radius of the incircle of a triangle is 8 cm. if the area of the triangle is 56 cm 2 , then its perimeter is?
The internal bisector of ∆ABC at ∠A cuts BC on D and cuts the circumcircle at E. If DE = 6cm, AC = 8cm and AD = 10 cm, then find the length of AB?
Find the area of triangle having sides 5 m, 6 m, and 9 m.
