A varies directly with B. When A=52, B=91. Find the value of A when B=126.
- A76
- B84
- C72
- D70
Solution & Step-by-step Explanation
Since A varies directly with B:
A∝B⟹A=kB
where k is a constant.
Given that A=52 when B=91:
52=k×91
k=
91
52
=
7×13
4×13
=
7
4
Now, we need to find A when B=126:
A=k×126
A=
7
4
×126
A=4×18=72
A∝B⟹A=kB
where k is a constant.
Given that A=52 when B=91:
52=k×91
k=
91
52
=
7×13
4×13
=
7
4
Now, we need to find A when B=126:
A=k×126
A=
7
4
×126
A=4×18=72