If \frac{421}{972} = \frac{1}{a + \frac{1}{b+ \frac{1}{c+ \frac{1}{d+ \frac{1}{e}}}}} then what is the value of a\times b\times c\times d\times e?
- A. 720 ✓
- B. 480
- C. 360
- D. 60
Correct Answer: A. 720
Explanation
We write 972/421 as a continued fraction: 972 = 2 \times 421 + 130 \implies a=2. Next, 421 = 3 \times 130 + 31 \implies b=3. Then, 130 = 4 \times 31 + 6 \implies c=4. Finally, 31 = 5 \times 6 + 1 \implies d=5 and e=6. The product is 2 \times 3 \times 4 \times 5 \times 6 = 720.
Related questions on Arithmetic
- What is the remainder when (17^{25} + 19^{25}) is divided by 18?
- A bottle contains spirit and water in the ratio 1:4 and another identical bottle contains spirit and water in the ratio 4:1. In what rat...
- Let P = 5^5 \times 15^{15} \times 25^{25} \times 35^{35} and Q = 10^{10} \times 20^{20} \times 30^{30} \times 40^{40}. What is the numbe...
- Two students X and Y appeared in a test. The score of X is 20 more than that of Y. If the score of X is 75% of the sum of the scores of X an...
- Question: The product of a natural number N and the number M written by the same digits of N in the reverse order is 252. What is the number...