Graduate Trainee Numerical Reasoning Dangote Cements Job

Let the principal be \(P\). Since the sum doubles in 5 years, the total amount becomes \(2P\). The simple interest formula is:\[SI = \dfrac{P \times R \times T}{100}\]Here, \(SI = 2P - P = P\).
Substitute into the formula:\[P = \dfrac{P \times R \times 5}{100}\]Cancel \(P\) from both sides:\[1 = \dfrac{R \times 5}{100}\]\[R = \dfrac{100}{5} = 20\%\]Therefore, the rate per annum is 20%.

The formula for the area of a circle is:\[A = \pi r^2\]Substitute \(r = 7\) cm and \(\pi = \dfrac{22}{7}\):\[A = \dfrac{22}{7} \times 7^2\]\[A = \dfrac{22}{7} \times 49\]\[A = 154\; \text{cm}^2\]Hence, the area of the circle is 154 cm².

Let the five consecutive even numbers be:
\(x, x + 2, x + 4, x + 6, x + 8\).
Their average is given by:\[\dfrac{x + (x + 2) + (x + 4) + (x + 6) + (x + 8)}{5} = 36\]\[\dfrac{5x + 20}{5} = 36\]\[x + 4 = 36\]\[x = 32\]Therefore, the smallest number is 32.

Let the number be \(x\).\[60\% \text{ of } x = 48\]\[\dfrac{60}{100} \times x = 48\]Multiply both sides by 100:\[60x = 4800\]Divide both sides by 60:\[x = 80\]Hence, the number is 80.

Convert 3 hours to minutes:\[3 \text{ hours} = 3 \times 60 = 180 \text{ minutes}\]Now form the ratio:\[180 : 45\]Divide both sides by 45:\[4 : 1\]Thus, the ratio of 3 hours to 45 minutes is 4:1.

The formula for population growth is:\[P = P_0 (1 + \dfrac{r}{100})^t\]Here, \(P_0 = 10,000\), \(r = 10\%\), and \(t = 2\) years.\[P = 10,000 (1 + \dfrac{10}{100})^2\]\[P = 10,000 (1.1)^2\]\[P = 10,000 \times 1.21 = 12,100\]Thus, the population after 2 years is 12,100.

To find the square root of 256, determine the number that when multiplied by itself gives 256.\[16 \times 16 = 256\]Therefore, \(\sqrt{256} = 16\).

Work done is inversely proportional to the number of men, assuming the same rate.\[\text{Men}_1 \times \text{Days}_1 = \text{Men}_2 \times \text{Days}_2\]\[5 \times 8 = 10 \times D_2\]\[40 = 10D_2\]\[D_2 = 4\]Hence, 10 men will complete the job in 4 days.

Time is given by:\[\text{Time} = \dfrac{\text{Distance}}{\text{Speed}}\]\[\text{Time} = \dfrac{180}{90} = 2\; \text{hours}\]Therefore, it takes 2 hours to cover 180 km at 90 km/h.

Simple interest (SI):\[SI = \dfrac{P \times R \times T}{100}\]\[SI = \dfrac{10,000 \times 10 \times 2}{100} = 2,000\] Compound interest (CI):\[CI = P \left(1 + \dfrac{R}{100}\right)^T - P\]\[CI = 10,000 (1.1)^2 - 10,000\]\[CI = 10,000 (1.21 - 1) = 2,100\] Difference:\[CI - SI = 2,100 - 2,000 = 100\] Therefore, the difference is ₦100.