Question

Q.17 Riya and Jiya are very health conscious and go for running every morning
Riya runs along the boundary of a square shaped park of side 20m and Jiya runs along a
triangular shaped park having sides 28m, 25m and 35m. Both takes four rounds
around the park.
Who runs longer distance by how much?
a) Riya by 32 m
b) Jiya by 32 m
c) Riya by 8 m
d) Jiya by 8 m
If both takes 5 minutes to complete one round of field, whose speed is less?
a) Riya
b) Jiya
c) Both have same speed
(iii) If Jiya runs around a rectangular park of side 25m and 30 m then how much
distance she cover in 1'2 round
a) 110 m
b) 220m
C) 165 m
d) 55m​

Answer 1

Solution :-

→ Side of square = 20 m .

→ Perimeter of square = 4 * side = 4 * 20 = 80 m .

so,

→ Distance covered by Riya in 4 rounds = 4 * perimeter = 4 * 80 = 320 m.

and,

→ sides of ∆ park = 28m, 25m and 35m.

→ perimeter = 28 + 25 + 35 = 88 m .

so,

→ Distance covered by Jiya in 4 rounds = 4 * perimeter = 4 * 88 = 352 m.

therefore,

→ Jiya covered more distance by = 352 - 320 = 32 m. (Ans.b)

now,

→ Distance covered by Riya = 320 m.

→ Time taken = 5 minutes .

so,

→ speed of Riya = Distance / speed = 320/5 = 64m/min.

and,

→ Distance covered by Jiya = 352 m.

→ Time taken = 5 minutes .

so,

→ speed of Jiya = Distance / speed = 352/5 = 70.4m/min.

therefore, speed of Riya is Less.

now,

→ Perimeter of rectangle = 2(Length + Breadth) = 2(25 + 30) = 2 * 55 = 110m .

hence,

→ Distance covered by Jiya in 1'2 rounds = 110 * 1.5 = 165 m. (Ans.)