Solve the equation for
t
t
by finding
a
a
,
b
b
, and
c
c
of the quadratic then applying the quadratic formula.
t
=
10
−
h
+
√
h
2
−
20
h
+
160
10
t
=
10
-
h
+
h
2
-
20
h
+
160
10
t
=
10
−
h
−
√
h
2
−
20
h
+
160
10
There would be 35 rulers.
In order to solve this, use cross multiplication.
6/10 = 21/x -----> cross multiply
10*21 = 6*x
210 = 6x
35 = x
You can multiply or you can estimate it!
Hope I could help
a: 2
b: 5
c 3
d: 4
I think the ans is 2
