Answer:
Grace jumped for 9 minutes and Zoe jumped for 12 minutes
Explanation:
Let Grace jumped for x minutes and Zoe jumped for y minutes
Grace jump no. of times in 1 minute = 66
Grace jump no. of times in x minutes = 66x
Zoe jump no. of times in 1 minute = 56
Zoe jump no. of times in x minutes = 56x
We are given that Their jumps today and together they jump 1266 times in the total of 21 minutes
So, x+y=21 ----1
66x+56y=1266 ---2
Substitute the value of x from 1 in 2
66(21-y)+56y=1266
y=12
x+y=21
x+12=21
x=21-12
x=9
Hence Grace jumped for 9 minutes and Zoe jumped for 12 minutes