What has many keys but can’t open a single lock?

Can you solve the below tricky visual equation?

Look at the picture and find out which square is not linked with any of the other squares.

John needs to purchase 100 chocolates from three different shops and he has exactly 100 rupees to do that which he must spend entirely. He must buy at least 1 Chocolate from each shop.

The first shop is selling each chocolate at 5 paise, the second is selling at 1 rupee and the third is selling at 5 rupees.

How many chocolates should he buy from each shop?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

What is at the end of a rainbow?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

Take one out and scratch my head, I am now black but once was red. What am I?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

Three brothers Jacob, John, and James live in Mexico City. The product of the ages of these brothers is 175. Jacob and John are twins. How old is James?