## Mathematics 2018 Past Questions | JAMB

Study the following Mathematics past questions and answers for JAMB, WAEC NECO and Post-JAMB. Get prepared with official past questions and answers for upcoming examinations.

**11. **Convert 0.04945 to two significant figures

**A.**0.040**B.**0.049**C.**0.050**D.**0.49

**Correct Option: Answer is B**

**12. **The probabilities that John and James pass an examination are \(\frac {3}{4}\)and \(\frac {3}{5}\) respectively. Find the probability of both boys failing the examination.

**A.**\(\frac {1}{10}\)**B.**\(\frac {2}{10}\)**C.**\(\frac {9}{20}\)**D.**\(\frac {11}{20}\)

**Correct Option: Answer is D**

Pr(both John and James passed)

= \(\frac {3}{4}\) x \(\frac {3}{5}\)

= \(\frac {9}{20}\)

Pr(john and james failed)= 1- Pr(john and james passed)

= 1 – \(\frac {9}{20}\)

= \(\frac {11}{20}\)

**13. **An arc of a circle of radius 14cm subtends angle 300° at the centre. Find the perimeter of the sector formed by the arc (take π = 22/$\frac{7}{}$)

**A.**14.67cm**B.**42.67cm**C.**101.33cm**D.**513.33cm

**Correct Option: Answer is C**

Perimeter of a sector =

Arc Length + Radius + Radius;

π= 22/7

∴ 300/360 x 2 x π x 14 + (14 + 14)

= 101.33cm

**14**. Simplify \(\frac {25^{\frac{2}{3}} \div 25^{\frac{1}{6}}} {(\frac{1}{5})^{\frac{7}{6}} \div (\frac{1}{5})^{\frac{1}{6}}}\)

**A.**25**B**\(\frac{1}{5}\)**C.**1**C.**\(\frac{1}{25}\)

**Correct Option: Answer is A**

\(\frac {25^{\frac{2}{3}} \div 25^{\frac{1}{6}}} {(\frac{1}{5})^{\frac{7}{6}} \div (\frac{1}{5})^{\frac{1}{6}}}\)

= \(\frac{25^{\frac{2}{3} – \frac{1}{6}}}{(\frac{1}{5})^{\frac{7}{6} – \frac{1}{6}}}\)

= \(\frac{25^{\frac{1}{2}}}{(\frac{1}{5})}\)

= \(5 \div \frac{1}{5}\)

= 25

**15.** \(\text{P} = \left[\frac{\mathrm{Q(R – T)}}{15}\right]^\frac{1}{3}\)

Make T the subject of the relation.

**A.**T = \(\frac{R + P3}{15Q}\)**B.**T = \(\frac{R – 15P^3}{Q}\)**C.**T =R – \(\frac{15P^3}{Q}\)**D.**T = \(\frac{15R + Q}{P^3}\)

**Correct Option: Answer is C**

**16. **What is the place value of 9 in the number 3.0492?

**A.**\(\frac{9}{10000}\)**B.**\(\frac{9}{1000}\)**C.**\(\frac{9}{100}\)**D.**\(\frac{9}{10}\)

**Correct Option: Answer is B**

**17. **If the simple interest on a sum of money invested at 3% per annum for 2 $\frac{\mathrm{1/}}{2}$ years is N123,

find the principal.

**A.**N676.50**B.**N820**C.**N1,640**D.**N4,920

**Correct Option: Answer is C**

SI = P T R

SI = 123 (Given)

T = 2.5 yrs

R = 3% or 0.03

∴ 123 = P x 2.5 x 0.03

P =123/0.075

∴ P = N1,640

**18. **A machine valued at N20,000 depreciates by 10% every year. What will be the value of the machine at the end of two years?

**A.**N16,200**B.**N14,200**C.**N12,000**D.**N8,000

**Correct Option: Answer is A**

Since it depreciates by 10% At the end of first year, its value = 90% of 20000

= \(\frac{90}{100}\) x 20000 =18000

At the end of second year, its value = 90% of 18000

= \(\frac{90}{100}\) x 18000 = ₦16,200

**19.** The table shown gives the marks scored by a group of student in a test. Use the table to answer the question given.

Mark | 0 | 1 | 2 | 3 | 4 | 5 |

Frequency | 1 | 2 | 7 | 5 | 4 | 3 |

What is the median mark?

**A.**1**B.**2**C.**3**D.**4

**Correct Option: Answer is C**

**20. **The table shown gives the marks scored by a group of student in a test. Use the table to answer the question given.

Mark | 0 | 1 | 2 | 3 | 4 | 5 |

Frequency | 1 | 2 | 7 | 5 | 4 | 3 |

What is the probability of selecting a student from the group that scored 2 or 3

**A.**\(\frac{1}{11}\)**B.**\(\frac{5}{22}\)**C.**\(\frac{7}{22}\)**D.**\(\frac{6}{11}\)