Theory question 108
Commercial Arithmetic(a) Lamin bought a book for N300.00 and sold it to Bola at a profit of x%. Bola then sold the same book to James at a profit of x%. If James paid N(6x + ¾) more for the book than what Lamin paid, find the value of x.
(b) Find the range of values of x which satisfies the inequality 3x − 2 < 10 + x < 2 + 5x.
Show the model answer
Model answer
(a) James paid 300(1 + x/100)²
300(1 + x/100)² − 300 = 6x + ¾ → 6x + 0.03x² = 6x + ¾
0.03x² = 0.75 → x² = 25 → x = 5
(b) 3x − 2 < 10 + x → x < 6; 10 + x < 2 + 5x → x > 2
So 2 < x < 6
Explanation
Split the double inequality into two and solve each.