#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 5;
template <typename T>
void chkmax(T &x, T y) {
  x = max(x, y);
}
template <typename T>
void chkmin(T &x, T y) {
  x = min(x, y);
}
template <typename T>
void read(T &x) {
  x = 0;
  int f = 1;
  char c = getchar();
  for (; !isdigit(c); c = getchar())
    if (c == '-') f = -f;
  for (; isdigit(c); c = getchar()) x = x * 10 + c - '0';
  x *= f;
}
template <typename T>
void write(T x) {
  if (x < 0) x = -x, putchar('-');
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
template <typename T>
void writeln(T x) {
  write(x);
  puts("");
}
double getp() {
  double x, y;
  read(x), read(y);
  return x / y;
}
struct info {
  double LtoR;
  double RtoR;
};
info operator+(info a, info b) {
  info ans;
  ans.LtoR = a.LtoR * b.LtoR / (1.0 - (1.0 - b.LtoR) * a.RtoR);
  ans.RtoR = b.RtoR +
             (1.0 - b.RtoR) * a.RtoR * b.LtoR / (1.0 - (1.0 - b.LtoR) * a.RtoR);
  return ans;
}
struct SegmentTree {
  struct Node {
    int lc, rc;
    info ans;
  } a[MAXN * 2];
  int n, size, root;
  void update(int root) { a[root].ans = a[a[root].lc].ans + a[a[root].rc].ans; }
  void build(int &root, int l, int r, double *val) {
    root = ++size;
    if (l == r) {
      a[root].ans = (info){val[l], val[l]};
      return;
    }
    int mid = (l + r) / 2;
    build(a[root].lc, l, mid, val);
    build(a[root].rc, mid + 1, r, val);
    update(root);
  }
  void init(int x, double *val) {
    n = x;
    root = size = 0;
    build(root, 1, n, val);
  }
  void modify(int root, int l, int r, int pos, double val) {
    if (l == r) {
      a[root].ans = (info){val, val};
      return;
    }
    int mid = (l + r) / 2;
    if (mid >= pos)
      modify(a[root].lc, l, mid, pos, val);
    else
      modify(a[root].rc, mid + 1, r, pos, val);
    update(root);
  }
  void modify(int pos, double val) { modify(root, 1, n, pos, val); }
  info query(int root, int l, int r, int ql, int qr) {
    if (l == ql && r == qr) return a[root].ans;
    int mid = (l + r) / 2;
    if (mid >= qr)
      return query(a[root].lc, l, mid, ql, qr);
    else if (mid + 1 <= ql)
      return query(a[root].rc, mid + 1, r, ql, qr);
    else
      return query(a[root].lc, l, mid, ql, mid) +
             query(a[root].rc, mid + 1, r, mid + 1, qr);
  }
  double query(int l, int r) {
    info ans = query(root, 1, n, l, r);
    return ans.LtoR;
  }
} ST;
int n, q;
double a[MAXN];
int main() {
  read(n), read(q);
  for (int i = 1; i <= n; i++) a[i] = getp();
  ST.init(n, a);
  for (int i = 1; i <= q; i++) {
    int opt, l, r, x;
    read(opt);
    if (opt == 1) {
      read(x);
      a[x] = getp();
      ST.modify(x, a[x]);
    } else {
      read(l), read(r);
      printf("%.10lf\n", ST.query(l, r));
    }
  }
  return 0;
}
