Advertisements
Advertisements
Question
Here is a key board of a harmonium:
- Find the ratio of white keys to black keys on the keyboard.
- What is the ratio of black keys to all keys on the given keyboard.
- This pattern of keys is repeated on larger keyboard. How many black keys would you expect to find on a keyboard with 14 such patterns.
Advertisements
Solution
According to the given figure,
a. The total number of black keys = 7
The total number of white keys = 10
Hence, the ratio of white keys to black keys on the keyboard = `10/7`
b. The total number of all keys = 10 + 7 = 17
The ratio of black keys to all keys on the given keyboard = `7/17`
c. Black keys in 1 keyboard = 7
Black keys in 14 such keyboards = 14 × 7 = 98 keys.
APPEARS IN
RELATED QUESTIONS
The amount of extension in an elastic string varies directly as the weight hung on it. If a weight of 150 gm produces an extension of 2.9 cm, then what weight would produce an extension of 17.4 cm?
Mohan takes 9 hours to mow a large lawn. He and Sohan together can mow it in 4 hours. How long will Sohan take to mow the lawn if he works alone?
A and B can do a piece of work in 18 days; B and C in 24 days and A and C in 36 days. In what time can they do it, all working together?
A and B can do a piece of work in 12 days; B and C in 15 days; C and A in 20 days. How much time will A alone take to finish the work?
A pipe can fill a cistern in 10 hours. Due to a leak in the bottom it is filled in 12 hours. When the cistern is full, in how much time will it be emptied by the leak?
A cistern can be filled by a tap in 4 hours and emptied by an outlet pipe in 6 hours. How long will it take to fill the cistern if both the tap and the pipe are opened together?
If 7 kg onions cost 140 rupees, how much must we pay for 12 kg onions?
Both x and y vary directly with each other and when x is 10, y is 14, which of the following is not a possible pair of corresponding values of x and y?
If 25 metres of cloth costs Rs 337.50, then what will be the length of the cloth bought for Rs 810?
A bowler throws a cricket ball at a speed of 120 km/h. How long does this ball take to travel a distance of 20 metres to reach the batsman?
