Problem: The times between 7 and 8 o′ clock, correct to the nearest minute, when the hands of a clock will form an angle of 84 degrees are:
Answer Choices:
A. 7:23 and 7:53
B. 7:20 and 7:50
C. 7:22 and 7:53
D. 7:23 and 7:52
E. 7:21 and 7:49
Solution:
210+x−12x=84;∴11x=126;
∴x=126/11,126⋅60/11⋅30∼23 and 210+x+84=12x
∴11x=294;∴x=294/11,294⋅60/11⋅30∼53
∴ the times are 7:23 and 7:53.