Question
Two candles of the same height are lighted at the same
time. The first is consumed in 10 hours and the second in 8 hours. Assuming that each candle burns at a constant rate, in how many hours after being lighted, the ratio between first and second candles becomes 4:1.Solution
Let the candle height is 1 meter. Let the required time =‘t’ hours In 10 hours first candle lighted = 1 So in 1 hour first candle lighted = t/10 After ‘t’ hours remaining first candle = (1 - t/10) Similarly, After ‘t’ hours remaining second candle = (1 - t/8) So the ratio between the first and second candle after being lighting = ((1 - t/10))/((1 - t/8)) = 4/1 1 - t/10 = 4 - (4t)/8 t/2 - t/10 = 4 – 1 (5t - t)/10 = 3 T = 15/2 hours or 7 hours 30 minutes
5466.97 - 3245.01 + 1122.99 = ? + 2309.99
(16.16 ×  34.98) + 14.15% of 549.99 = ? + 124.34
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exactvalue.)
15.232 + 19.98% of 539.99 = ? × 8.99
(31.9)3 + (34.021)² - (16.11)3 - (42.98)² = ?
What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)...
`sqrt(7.987 X 24.790 +199.991)`
19.99% of 79.98 = ?2– 159.99% of 12.5
(18.21)² - (12.9)² = 20% of 649.9 - ? + 400.033
2875.45 + ? – 2762.19 = 2145.72 – 1956.63