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
A 5 m 60 cm high vertical pole casts a shadow 3 m 20 cm long. Find at the same time the height of a pole which casts a shadow 5 m long.
A loaded truck travels 14 km in 25 minutes. If the speed remains the same, how far can it travel in 5 hours?
Explain the concept of direct variation.
In a library 136 copies of a certain book require a shelf-length of 3.4 metre. How many copies of the same book would occupy a shelf-length of 5.1 metres?
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 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?
The perimeter of a circle and its diameter vary ______ with each other.
Write whether the following statement vary directly, vary inversely with each other, or neither of the two.
Area of land and its cost.
The mass of an aluminum rod varies directly with its length. If a 16 cm long rod has a mass of 192 g, find the length of the rod whose mass is 105 g.
There are 20 grams of protein in 75 grams of sauted fish. How many grams of protein is in 225 gm of that fish?
