JAMB Mathematics Past Questions & Answers - Page 221

Let x represents number of boys that can work at $\frac{5}{4}$ the rate at which the 10 girls work

For 1hr. x boys will work for $\frac{\frac{1}{5}}{4}$ x 10

x = $\frac{4}{5}$ x 10 = 8 boys

8 boys will do the work of ten girls at the same rate 4 + 8 = 12 boys cut the field in 5 hrs

For 3 hrs, $\frac{12 \times 5}{3}$ boys will be needed = 20 boys

profit 8% of N1.35 = $\frac{8}{100}$ x N1.35 = N0.08

Cost price = N1.35 - N0.10 = N1.25

If he sells the 20 oranges for N1.10 now

%loss = $\frac{\text{actual loss}}{\text{Cost price}}$ x 100

$\frac{125 - 1.10}{1.25}$ x 100

= $\frac{0.15 \times 100}{1.25}$

= $\frac{15}{1.25}$

= 12%

I = $\frac{PRT}{100}$

100(A - P) = prt

P = $\frac{100A}{100 + RT}$

= $\frac{100 \times 7000}{100 + (4 \times 3)}$

p = $\frac{700,000}{112}$

= N6,250.00

Total amount invested by A and B = N5,000

farm yield was sold for N15,000.00

profit = 15,000.00 - 5,000.00

= N10,000.00

Profit was shared in ratio 2 : 3

2 + 3 = 5

A received $\frac{2}{5}$ of profit = $\frac{2}{5}$ x 10,000 = N4,000.00

A receive $\frac{3}{5}$ of profit = $\frac{3}{5}$ x 10,000 = N6,000.00

Difference in profit received = N6,0000 - N4,000.00

= N2,000.00

Length and width of a square is 100%

Length increased by 20% and

Width decreased by 20% to form a rectangle

Length of rectangle = 120% to form a rectangle

Length of rectangle = 120% and

Width of rectangle = 80%

Area of rectangle = L x W

Area of square = W

Ratio of the area of the rectangle to the area of the square

A = $\frac{\text{Area of rectangle}}{\text{Area of square}}$

$\frac{120 \times 30}{100 \times 100}$ = $\frac{96}{100}$

= 24 : 25