Integers a, b, c, d are such that −5≤a≤4, −2≤b≤6, −3≤c≤8 and −4≤d≤6. If X = ab + bc + cd + da, then find the least value of X?
-96
-72
48
-144
There are only 2 possibilities for minimum value -
Thus, the answer is option (a).
AB and CD are two common tangents to circles which touch each other at C. If D lies on AB such that CD = 4 cm, then find the length of AB.
If 4x+85x+8=56, then x = ?
(a) 4
(b) 6
(c) 8
(d) 12