## Shortcut Tricks to Solve Problems on Mensuration - 2

## Effective for IBPS PO - SBI PO Exam

**Dear Reader,**

Here we will start a series of Quantitative Aptitude Shortcut Tricks for your upcoming SBI - IBPS - SSC and Other Government Competitive Exams. We will try to cover up all topics of the quantitative Aptitude Sections from which question was generally asked.

**Note:**The page may takes sometime to load the Quantitative formula's. If you face any problem just comment below the posts.

**Trick - 1**

- If a circular wire of radius x units is cut and bent in the form of a rectangle whose sides are in the ratio of a:b, then the sides of the rectangle are given by

$\left[
\pi x\left( \frac{a}{a+b} \right) \right]units$ and $\left[
\pi x\left( \frac{b}{a+b} \right) \right]units$

**Trick - 2**

- If the radius of a right circular cylinder is changed by x % and height is changed by y%, then curved surface area changes by

$\left[
x+y+\frac{xy}{100} \right]percent$

**Trick - 3**

- If radius of a right circular cylinder is changed by x % and height is changed by y% then volume changes by

$\left[
2x+y+\frac{{{x}^{2}}+2xy}{100}+\frac{{{x}^{2}}y}{{{100}^{2}}} \right]percent$

**Trick - 4**

- If radius of a right circular cylinder is changed by x % and height remains the same the volume changes by

$\left[
2x+\frac{{{x}^{2}}}{100} \right]percent$ or $\left[
{{\left( 1+\frac{x}{100} \right)}^{2}}-1 \right]\times100 percent$

**Trick - 5**

- If height and radius of a right circular cylinder both changes by x%, then volume changes by

$\left[
3x+\frac{3{{x}^{2}}}{100}+\frac{{{x}^{3}}}{{{100}^{2}}} \right]percent$

**Trick - 6**

- If side of a cube is increased by x% then its surface area increases by

$\left(
2x+\frac{{{x}^{2}}}{100} \right)percent$

**Questions for Practice****Q1.**

**A circular wire of radius 42 cm is cut and bent in the form of a rectangle whose sides are in the ratio of 6 : 5. Find the smaller side of the rectangle.**

**Q2. T**

**he radius and height of a cylinder are increased by 10 % and 20% respectively. Find the percent increase in its curved surface area.**

**Q3.**

**The radius of a right circular cylinder is decreased by 10% but its height is increased by 15%. What is the percentage change in its volume ?**

**Q4.**

**The radius of a cylinder is increased by 25 %. Keeping its height unchanged. What is the percentage increase in its volume ?**

**Q5.**

**Each of the radius and the height of a right circular cylinder is both increased by 10%. Find the % by which the**

**volume**

**increases.**

**Q6. Each edge of a cube is increased by 50%. What is the percentage increase in its volume ?**

__Answers__**Answer 1. 60 cm**

**Answer 2. 32%**

**Answer 3. 6.85%**

**Answer 4. 56.25%**

**Answer 5. 33.1%**

**Answer 6. 125%**

## Post a Comment