Private tutors set their own rates and often offer discounts for larger bookings, but the average rate paid in the UK is £22.30 per hour according to research by First Tutors.
The price tends to vary by the level of education, ranging from just over £20 per hour for primary school pupils to £26.56 for university level.
Tutors are most expensive in Brighton (£24.53) and least expensive in Newcastle (£18.16).
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The Metropolitan Police Federation, which set up the official JustGiving site, said it felt a "suitable amount" had been collected.
There is no evidence the Westminster attacker Khalid Masood was associated with so-called Islamic State or al Qaeda, the Met Police said.
Janet Ajao said in a statement: "I do not condone his actions nor support the beliefs he held that led to him committing this atrocity."