Question
The average of six numbers is 8. When three new numbers
are included in such a way that the first number is  twice the second and second number is thrice the third, now the average of nine numbers becomes 12. What will be the difference of first and third among the new numbers?ÂSolution
Sum of five numbers = 6 × 8 = 48 Let the third number be x, Second number will be 3x, First number will be 6x According to the question, (48+6x+3x+x)/9=12 ;  (48+10x)/9=12; x=  (108-48)/10 x=6 ∴ the three numbers will be 6, 18 and 36 ∴ Difference of first and third no.= 36 – 6 = 30
What will be inradius of an equilateral triangle of side 10 cm?
In ΔABC, PQ is parallel to BC If AP: PB= 3:4 and AQ= 6 cm, AC is equal to?
AB is parallel to DC in a trapezium ABCD. It is given that AB > DC and the diagonals AC and BD intersect at O. If AO=3x-15, OB = x +9, OC =x-5 and OD = ...
- A tangent is drawn from an external point P to a circle, touching the circle at point Q such that PQ = 16cm. A secant PRS is also drawn from P, intersectin...
If I is the incentre of ΔABC , if ∠BAC = 800 , then what is the measure of ∠BIC?
The lengths of three medians in a triangles are 15 cm, 20 cm, 25 cm. What is the area of that traingle (in cm 2 )?
Find the area of the region enclosed by the curves : y = 0, x = |y| and y = |x - 2|.
∆ABC and ∆DEF are similar and their areas are respectively 16 cm2 and 64 cm 2 . If EF = 6 cm BC is?
If in a ΔABC, AD is internal angle bisector & D is a point on BC, AB = 9 cm, BC = 12 cm then what is BD:CD?
A and B are the centres of two circles with radii 11 cm and 6 cm respectively. A common tangent touches these circles at P & Q respectively. If AB =...
Relevant for Exams:
