Question
Find the sum of all those 3-digit numbers which when
divided by 10 leave a remainder of 5.Solution
Numbers 105, 115, 125, ……985, 995 first number (a) = 105 The last number (8) = 995 All difference (d) =10 From the formula, nth term (Tn) = a + (n-1) d, 995=105+(n-1) 10  n = 90  Sum of n terms (Sn) =n/2 [2a+(n-1) d]  90/2[2 ×105+ (90-1)10] = 45 [210+890] = 45 × 1100  = 49500.
- In triangle XYZ, lines XP and PF are medians of triangle XYZ and triangle XZF respectively. If the area of triangle XPF is 15 cm², calculate the area of t...
Given a right-angled triangle with the perpendicular measuring 36 cm and the base measuring 48 cm, determine the length of the shortest median of the tr...
The base of a pyramid is an equilateral triangle whose side is 8 cm. Is. Its (slant edge) is 24 cm. What is the total surface area (in cm²) of the pyra...
The parallel sides of a trapezium and its height are in an arithmetic progression with a common difference of 4. If the height is the highest term and t...
In the Figure given below, find the value of x?
- The base of a right pyramid is an equilateral triangle with side 9 cm. If the height of the pyramid is 45√3 cm, find the volume of the pyramid.
- Find the distance between the parallel sides of a trapezium whose area is 315 cm² and the lengths of the parallel sides are 15 cm and 21 cm respectively.
The area of an isosceles triangle ABC is 8√5 cm 2 . If AB = BC and AC = 8 cm, then find the perimeter of triangle ABC.
Two triangles DEF and XYZ are similar to each other. If DE = 5 cm, DF = 7 cm, and XY = 15 cm, then find XZ.
A right-angled triangle has one leg of 12 cm and the hypotenuse of 13 cm. Find the length of the other leg.
Relevant for Exams:
