(a) Let the first five days be a,b,c,d and e. Given,
a
c
=
7
8
∴ a = 7 x and c = 8x. According to the given condition, a + b + c +d =58 x 4 = 232 ∴ 7x + (b + c + d ) = 232 ...(i) and b + c + d + e = 60 x 4 = 240 (b+c+d)+ 8x = 240 232 - 7x + 8x = 240 [from Eq. (i)] ⇒ x = 8 Temperative on fifth day, e = 8x = 8 × 8 = 64 days