diff --git a/questions/116-medium-replace/README.md b/questions/116-medium-replace/README.md
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+Implement `Replace<S, From, To>` which replace the string `From` with `To` once in the given string `S`
+
+For example
+
+```ts
+type replaced = Replace<'types are fun!', 'fun', 'awesome'> // expected to be 'types are awesome!'
+```
diff --git a/questions/116-medium-replace/info.yml b/questions/116-medium-replace/info.yml
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+difficulty: medium
+title: Replace
+tags: template-string
+tsconfig:
+  ts: 4.1.0-pr-40336-88
+author:
+  github: antfu
+  name: Anthony Fu
+
diff --git a/questions/116-medium-replace/template.ts b/questions/116-medium-replace/template.ts
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+++ b/questions/116-medium-replace/template.ts
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+type Replace<S extends string, From extends string, To extends string> = any
diff --git a/questions/116-medium-replace/test-cases.ts b/questions/116-medium-replace/test-cases.ts
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+import { Equal, Expect } from '@type-challenges/utils'
+
+type cases = [
+  Expect<Equal<Replace<'foobar', 'bar', 'foo'>, 'foofoo'>>,
+  Expect<Equal<Replace<'foobarbar', 'bar', 'foo'>, 'foofoobar'>>,
+  Expect<Equal<Replace<'foobarbar', '', 'foo'>, 'foobarbar'>>,
+  Expect<Equal<Replace<'', '', ''>, ''>>,
+]