Answer:
total number of grey key is = 7
and total number of black key is = 11
Explanation:
Given data:
Total number of keys - 50
number of grey key is 7
number of black key is 11
so we have ratio of grey and black key = 7:11
let total number of grey key is 7x
and total number of black key is 11x
from the information in question we have
11x = 2\times 7x -2
11x = 14x - 2
x = 1
so total number of grey key is = 7*1 = 7
and total number of black key is = 11