#include <bits/stdc++.h>
using namespace std;
const int maxn = 101000;
struct node {
  double p, sp;
} tr[maxn * 6];
int n, m;
void pushup(int st) {
  tr[st].p = (tr[st << 1].p * tr[st << 1 | 1].p);
  tr[st].sp = tr[st << 1].sp + tr[st << 1 | 1].sp * tr[st << 1].p;
}
void build(int l, int r, int st) {
  if (l == r) {
    double a, b, p;
    scanf("%lf %lf", &a, &b);
    p = a / b;
    tr[st].p = tr[st].sp = (1 - p) / p;
    return;
  }
  int mid = (l + r) >> 1;
  build(l, mid, st << 1);
  build(mid + 1, r, st << 1 | 1);
  pushup(st);
}
void change(int l, int r, int st, int x) {
  if (l == r) {
    double a, b, p;
    scanf("%lf %lf", &a, &b);
    p = a / b;
    tr[st].p = tr[st].sp = (1 - p) / p;
    return;
  }
  int mid = (l + r) >> 1;
  if (x <= mid)
    change(l, mid, st << 1, x);
  else
    change(mid + 1, r, st << 1 | 1, x);
  pushup(st);
}
double p, sp;
void Query(int l, int r, int st, int L, int R) {
  if (L == l && R == r) {
    sp += tr[st].sp * p;
    p *= tr[st].p;
    return;
  }
  int mid = (l + r) >> 1;
  if (R <= mid)
    Query(l, mid, st << 1, L, R);
  else if (L > mid)
    Query(mid + 1, r, st << 1 | 1, L, R);
  else {
    Query(l, mid, st << 1, L, mid);
    Query(mid + 1, r, st << 1 | 1, mid + 1, R);
  }
}
int main() {
  scanf("%d %d", &n, &m);
  build(1, n, 1);
  int op, l, r;
  while (m--) {
    scanf("%d", &op);
    if (op == 1) {
      scanf("%d", &l);
      change(1, n, 1, l);
    } else {
      p = 1;
      sp = 0;
      scanf("%d %d", &l, &r);
      Query(1, n, 1, l, r);
      double ans = 0;
      if (sp < 1e15) ans = (1.0 / (sp + 1));
      printf("%.10f\n", ans);
    }
  }
  return 0;
}
