Question

Mary and peter had a total of RS 480. After peter spent Rs 20, he had 3 times as much as mary.How much did mary have? Solution?

Answer 1

let amount with mary = Rs x

let amount with peter = Rs y

given that

x + y = 480     ------------------------- eq 1

amount with peter after he spent rs 20 = y - 20

for second given condition

y -20 = 3 × x

y - 3x = 20   ------------------------------eq 2

eq1 - eq2 , we get

x + y - y + 3x = 480 - 20

⇒ 4x = 460

⇒ x = 460/4 = 115

Mary have Rs 115.