Question

Please help me to figure out this question. Thanks

Answer 1

Answer:

a) 5 : 7

b) 25 black keys

c) 100 black keys will appear.

Step-by-step explanation:

a) From the picture,

There are 5 black keys and 7 white keys.

Therefore, the ratio of black keys to white keys are = 5 : 7 = 5/7

b) If the pattern continues, 25 black keys will be appeared on a portable full-sized keyboard.

Explanation -

From part A, we get the ratio of black keys to white keys = 5 : 7. Therefore,

If there are 7 white keys, there are 5 black keys

If there are 1 white keys, there are 5/7 black keys

If there are 35 white keys, there are (5*35)/7 black keys

= 25 black keys.

c) If there are 240 keys, the black keys will appear -

We get, the ratio of black keys to white keys = 5 : 7

The summation of the black keys and white keys = (5 + 7) = 12.

Therefore, if there are 240 keys, the black keys will be

= (5/12) x 240

= (5 x 240)/12

= 100

Therefore, there are 100 black keys.