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
Fill in the blank in of the following so as to make the statement true:
If u = 3 v, then u and v vary .... with each other.
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 polish the floors of a building in 10 days. A alone can do \[\frac{1}{4}\] th of it in 12 days. In how many days can B alone polish the floor ?
A can do a piece of work in 40 days and B in 45 days. They work together for 10 days and then B goes away. In how many days will A finish the remaining work?
A postman can sort out 738 letters in 6 hours. How many letters can be sorted in 9 hours?
If x and y are in direct proportion, then (x – 1) and (y – 1) are also in direct proportion.
The area of cultivated land and the crop harvested is a case of direct proportion.
Write whether the following statement vary directly, vary inversely with each other, or neither of the two.
Income tax and the income.
Write whether the following statement vary directly, vary inversely with each other, or neither of the two.
Area of land and its cost.
Here is a keyboard of a harmonium: 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.
