Using Only Five 5's and any mathematical operator make sum as 37

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?