1. If \(62\frac{1}{2}\)% of a number is added with itself then the result becomes 1560. Find the original number.
Sol:
⟹ 5 + 8 = 13 ⟶ 1560
1 ⟶ 120
∴ original number = 8 × 120 = 960 Answer
2. If \(37\frac{1}{2}\)% of a number is subtracted from itself then the result becomes 10500. Find the original number.
Sol:
3. If \(16\frac{2}{3}\)% of a number is added with itself then the result becomes 15684. Find the original number.
Sol:
4. If \(157\frac{1}{7}\)% of a number is subtracted from itself then the result becomes -2032. Find the original number.
Sol:
5. If \(11\frac{1}{9}\)% of a number is added with itself then the result becomes 1800. Find the original number.
Sol:
6. What is 10% of 40% of 75% of 90.
Sol:
\(\frac{1}{{10}} \times \frac{4}{{10}} \times \frac{3}{4} \times 90\)
= \(\frac{3}{{10}} \times 9\)
= \(\frac{{27}}{{10}}\)
= 2.7 Answer
7. If 10% of (A + B) = 30% of (A – B) then find A:B.
Sol:
10% × (A + B) = 30% × (A – B)
\(\frac{1}{{10}}\)(A + B) = \(\frac{3}{{10}}\)(A – B)
A + B = 3A – 3B
⟹ 4B = 2A
⟹ \(\frac{A}{B} = \frac{4}{2}\)
= 2:1 Answer
8. 25% of what number is 40.
Sol:
9. If 72 is added in a number then number becomes \(57\frac{1}{7}\)% of itself. Find the number.
Sol:
10. If 1953 is added in a number then number becomes \(444\frac{4}{9}\)% of itself. Find the original number.
Sol: