All Exams Test series for 1 year @ ₹349 only
Question

A pyramid with an equilateral triangular base of side 10 cm and height 14 cm is placed on top of a cube with side length 10 cm. Find the total volume of the composite solid.

This question was previously asked in
SSC CGL 2025 Tier 1 Question Paper (25-Sep-2025) (Shift 3)
The correct answer is
$1202.07 \text{ cm}^3$

Composite Solid Volume Calculation

The problem asks for the total volume of a composite solid formed by placing a pyramid on top of a cube.

The total volume is the sum of the volume of the cube and the volume of the pyramid.

Vtotal = Vcube + Vpyramid

Volume of the Cube

The cube has a side length s = 10 cm.

The formula for the volume of a cube is:

Vcube = s3

Substituting the value:

Vcube = (10 \text{ cm})^3 = 1000 \text{ cm}^3

Volume of the Pyramid

The pyramid has an equilateral triangular base with side length a = 10 cm and a height hpyramid = 14 cm.

First, calculate the area of the equilateral triangular base (Base Area):

\text{Base Area} = \frac{\sqrt{3}}{4} a^2

\text{Base Area} = \frac{\sqrt{3}}{4} (10 \text{ cm})^2 = \frac{\sqrt{3}}{4} \times 100 \text{ cm}^2 = 25\sqrt{3} \text{ cm}^2

Using the approximation $\sqrt{3} \approx 1.73205$:

\text{Base Area} \approx 25 \times 1.73205 \approx 43.301 \text{ cm}^2

The formula for the volume of a pyramid is:

Vpyramid = \frac{1}{3} \times \text{Base Area} \times h_{pyramid}

Substituting the values:

Vpyramid} = \frac{1}{3} \times (25\sqrt{3} \text{ cm}^2) \times (14 \text{ cm})

Vpyramid} = \frac{350\sqrt{3}}{3} \text{ cm}^3

Calculating the approximate value:

Vpyramid} \approx \frac{350 \times 1.73205}{3} \approx \frac{606.2175}{3} \approx 202.07 \text{ cm}^3

Total Volume Calculation

Add the volume of the cube and the volume of the pyramid:

Vtotal = Vcube + Vpyramid

Vtotal} \approx 1000 \text{ cm}^3 + 202.07 \text{ cm}^3

Vtotal} \approx 1202.07 \text{ cm}^3

Was this answer helpful?

Similar Questions

  1. The base area of a prism is increased by 25%, while the height remains the same. By what percentage does the volume increase?
  2. In a right prism with a square base, volume = $1024 \text{ cm}^3$ and height = 16 cm. What is the side of the square base?
  3. If the numerical value of the volume of a sphere is equal to the numerical value of its surface area, find the radius of the sphere.
  4. A water tank is shaped like a composite prism: the bottom part is a triangular prism with base area 60 cm² and height 1.2 m, while the top part is a rectangular prism with base 40 cm × 30 cm and height 0.8 m. What is the total volume of the tank in liters? (1 m³ = 1000 L)
  5. A company designs a new chocolate box in the shape of a regular right pyramid with a square base. The base side of the box is 10 cm and its height is 12 cm. Due to packaging constraints, the box can only be filled up to 90% of its total volume. If the company wants to estimate the total cost of chocolate, knowing that $1 \text{ cm}^3$ of chocolate costs ₹0.50, what is the cost of chocolate to fill one such box?
  6. A right prism has a base in the shape of a trapezium with parallel sides 10 cm and 6 cm, and height 4 cm. If the prism height is 15 cm, what is the volume?
  7. A pyramid is inscribed inside a cube with edge 12 cm, sharing the base and apex at center of top. Find volume of pyramid.
  8. A storage box is in the shape of a right rectangular prism with internal dimensions 50 cm $\times$ 40 cm $\times$ 30 cm. How many liters can it hold?
  9. A spherical balloon is inflated causing its radius to grow by 10%. By what percentage does its surface area increase?
  10. A bucket can hold 6.25 liters of water. How many such buckets are needed to fill a 1 cubic meter tank?

Important Questions from 3-D Mensuration

  1. Find the surface area of a sphere whose diameter is equal to 98 cm.
  2. A conical vessel has base radius 31 cm and height 45 cm. Water is poured into the vessel until it is $\frac{2}{3}$ full. Find the volume (in cm³) of water in the vessel.
  3. A solid metallic sphere of radius 10 cm is melted and recast into 125 identical spheres. What is the ratio of the surface area of the original sphere to the total surface area of 6 smaller spheres so formed?
  4. Find the volume (in cm³) of the largest right circular cone that can be cut out from a cube with an edge of 8 cm. Use $\pi = \frac{22}{7}$
  5. The volume of a solid cylinder is 5852 cm³ and its height is 38 cm. What is the total surface area of the solid cylinder? (Round your answer to the nearest integer) (Use $\pi = \frac{22}{7}$)
Need Expert Advice?
Test Series
SSC CGL img
SSC
SSC CGL (Tier I + Tier II) 2026 Mock Test Series - Latest Pattern
1736 Tests 6 Tests Free
1855 Attempts
4.2(846)
English, Hindi

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App