JAMB Mathematics Past Questions & Answers - Page 226

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